Journal articles on the topic 'Gravitational essence'
To see the other types of publications on this topic, follow the link: Gravitational essence.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 49 journal articles for your research on the topic 'Gravitational essence.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Cooperstock, F. I. "The essence of gravitational waves and energy." International Journal of Modern Physics D 24, no. 12 (October 2015): 1543005. http://dx.doi.org/10.1142/s0218271815430051.
Full textAbstract:
In this paper, we discuss the essential element of gravity as spacetime curvature and a gravitational wave as the propagation of spacetime curvature. Electromagnetic waves are necessarily localized carriers of spacetime curvature and hence are also gravitational waves. Thus, electromagnetic waves have dual character and detection of gravitational waves is the routine of our everyday experience. Regarding the transferring energy from a gravitational wave to an apparatus, both Rosen and Bondi waves lack the essential characteristic of inducing a gradient of acceleration between detector elements. We discuss our simple invariant energy expression for general relativity and its extension. If the cosmological term is present in the field equations, its universal presence characteristic implies that gravitational waves would necessarily have an energy aspect in their propagation in every case.
2
Aldrovandi, R., J. G. Pereira, and K. H. Vu. "The Nonlinear Essence of Gravitational Waves." Foundations of Physics 37, no. 10 (September 11, 2007): 1503–17. http://dx.doi.org/10.1007/s10701-007-9180-2.
Full text
3
Dmitriev, Alexander L. "Gravitational Induction as Analog of Amplification of Light in Active Medium." Applied Physics Research 9, no. 5 (September 10, 2017): 87. http://dx.doi.org/10.5539/apr.v9n5p87.
Full textAbstract:
Concept of gravitational induction the essence of which is in the change of gravitation force affecting test mass due to influence of gravitational field on this mass by other masses has been considered. Evaluation of coefficient of induced increase of the gravity in the titanium sample has been shown based on the measurement of weight of nonmagnetic metal rod by its vertical and horizontal orientation.
4
Haug, Espen Gaarder. "Gravity Without Newton’s Gravitational Constant and No Knowledge of the Mass Size." European Journal of Applied Physics 4, no. 6 (November 17, 2022): 4–10. http://dx.doi.org/10.24018/ejphysics.2022.4.6.223.
Full textAbstract:
In this paper, we show that the Schwarzschild radius can be extracted easily from any gravitationally-linked phenomena without having knowledge of Newton’s gravitational constant or the mass size of the gravitational object. Further, the Schwarzschild radius can be used to predict a long series of gravity phenomena accurately, again without knowledge of Newton’s gravitational constant and also without knowledge of the size of the mass, although this may seem surprising at first. Hidden within the Schwarzschild radius are the more fundamental mass of the gravitational object, the Planck length, which we will assert contain the secret essence related to gravity, in addition to the speed of light (the speed of gravity). This seems to support that gravity is quantized, even at the cosmological scale, and this quantization is directly linked to the Planck units. This also supports our view that Newton’s gravitational constant is a universal composite constant of the form G = l2pc3/h , rather than relying on the Planck units as a function of G. This does not mean that Newton’s gravitational constant is not a universal constant, but rather that it is a composite universal constant, which depends on the Planck length, the speed of light, and the Planck constant. This is, to our knowledge, the first paper1 that shows how a long series of major gravity predictions and measurements can be completed without any knowledge of the mass size of the object, or Newton’s gravitational constant. At minimum, we think it provides an interesting new angle for evaluating existing theories of gravitation.
5
CHIMENTO, LUIS P., and ALEXANDER FEINSTEIN. "POWER-LOW EXPANSION IN k-ESSENCE COSMOLOGY." Modern Physics Letters A 19, no. 10 (March 28, 2004): 761–68. http://dx.doi.org/10.1142/s0217732304013507.
Full textAbstract:
We study spatially flat isotropic universes driven by k-essence. It is shown that Friedmann and k-field equations may be analytically integrated for arbitrary k-field potentials during evolution with a constant baryotropic index. It follows that there is an infinite number of dynamically different k-theories with equivalent kinematics of the gravitational field. We show that there is a large "window" of stable solutions, and that the dust-like behavior separates stable from unstable expansion. Restricting to the family of power law solutions, it is argued that the linear scalar field model, with constant function F, is isomorphic to a model with divergent speed of sound and this makes them less suitable for cosmological modeling than the nonlinear k-field solutions we find in this paper.
6
Razina, Olga, Pyotr Tsyba, Bekdaulet Meirbekov, and Ratbay Myrzakulov. "Cosmological Einstein–Maxwell model with g-essence." International Journal of Modern Physics D 28, no. 10 (July 2019): 1950126. http://dx.doi.org/10.1142/s0218271819501268.
Full textAbstract:
In this paper, we study the model of the late universe with the homogeneous, isotropic and flat Friedmann–Robertson–Walker metric, where the source of the gravitational field is based on the fermion and boson fields, with the Maxwell term [Formula: see text] in four dimensions. The actuation of the Maxwell term for the Einstein gravity makes it possible to find new approaches to solve the problem of the observed accelerated expansion of the universe. Energy conditions have been obtained and studied. These conditions impose very simple and model-independent restrictions on the behavior of energy density and pressure since they do not require a specific equation-of-state of matter. To consider the model, the energy conditions NEC, WEC, DEC are realized, and the SEC condition is violated. The boson and fermion fields are responsible for the accelerated regime at early times, but since the total pressure tends toward zero for large times, a transition to a decelerated regime occurs. Maxwell field is crucial only in the early times.
7
Сhaban, Vasil. "IMPACT OF THE INTERACTION OF MOVING PLANETS ON THEIR ORBITS." Measuring Equipment and Metrology 83, no. 2 (2022): 11–16. http://dx.doi.org/10.23939/istcmtm2022.02.011.
Full textAbstract:
The research raises the problem of determining and measuring the interaction of planets on the trajectory of their orbits around the Sun. Its solution becomes possible only based on an adequate mathematical model. For this purpose, Newton's law of universal gravitation was adapted to the case of moving masses in a wide range of velocities in flat Euclidean space and physical time. The finite speed of propagating the gravitational field is considered. Differential equations of planets’ motion are obtained. Transients in the three-mass system of a star and two planets close to the Sun-Mercury-Venus system are simulated. To reveal deeply the essence of physical interaction, a hyperbolized transition process is simulated under artificially close moving masses.
8
Anđelković, Bojan. "From Retrogradism to Post-Gravitational Art and Back." Maska 31, no. 177 (June 1, 2016): 51–57. http://dx.doi.org/10.1386/maska.31.177-178.51_1.
Full textAbstract:
Dragan Živadinov creates conceptual total works of art that are procedural and processual in nature. At the centre of interest of his art is the spectator, or the gaze, since the essence of this theatre is produced by a constant turning of the perspective. The project(ile) Noordung 1995-2045 has been conceived as a 50-year project to show the instability of the relation between body and technology. It stages itself and thus repeats the drama of the cosmos. A theatre of repetition that again finds the primary (ritual) sense of theatre.
9
Gonçalves, J. S., and A. F. Santos. "A study on causality in f(R,ϕ,X) theory." International Journal of Modern Physics A 36, no. 02 (January 20, 2021): 2150009. http://dx.doi.org/10.1142/s0217751x21500093.
Full textAbstract:
The [Formula: see text]-essence modified [Formula: see text] gravity model, i.e. [Formula: see text] theory is studied. The question of violation of causality, in the framework of Gödel-type universes, is investigated in this gravitational model. Causal and noncausal solutions are allowed. A critical radius for noncausal solution is calculated. It is shown that the violation of causality depends on the content of matter.
10
SHARIFIAN, MOSTAFA, and AHMAD SHEYKHI. "SCALAR FIELDS RECONSTRUCTION OF VISCOUS GDE WITH VARYING G." International Journal of Modern Physics D 23, no. 01 (January 2014): 1450002. http://dx.doi.org/10.1142/s0218271814500023.
Full textAbstract:
In this paper, we first study the effects of the varying gravitational constant G as well as the bulk viscosity on the evolution of the Universe field with pressureless dark matter and ghost dark energy (GDE). Then, we establish a correspondence between viscous GDE and scalar field models of dark energy including quintessence, tachyon, K-essence and dilaton energy density in a flat FRW universe. This correspondence allows us to reconstruct the potential and dynamics of the scalar fields according to the evolution of interacting viscous GDE with varying G.
11
CASTRO, CARLOS. "LANCZOS–LOVELOCK–CARTAN GRAVITY FROM CLIFFORD-SPACE GEOMETRY." International Journal of Geometric Methods in Modern Physics 10, no. 06 (April 30, 2013): 1350019. http://dx.doi.org/10.1142/s0219887813500199.
Full textAbstract:
A rigorous construction of Clifford-space (C-space) gravity is presented which is compatible with the Clifford algebraic structure and permits the derivation of the expressions for the connections with torsion in C-spaces. The C-space generalized gravitational field equations are derived from a variational principle based on the extension of the Einstein–Hilbert–Cartan action. We continue by arguing how Lanczos–Lovelock–Cartan (LLC) higher curvature gravity with torsion can be embedded into gravity in C-spaces and suggest how this might also occur for extended gravitational theories based on f(R), f(Rμν), … actions, for polynomial-valued functions. In essence, the LLC curvature tensors appear as Ricci-like traces of certain components of the C-space curvatures. Torsional gravity is related to higher-order corrections of the bosonic string-effective action. In the torsionless case, black-strings and black-brane metric solutions in higher dimensions D > 4 play an important role in finding specific examples of solutions to LL gravity.
12
Wang, Xijia. "New Explanation on Essence of Quantum Phenomena and Interactions and the Gravitational Action in Cosmic Continuum Theory." International Journal of Applied Physics 7, no. 3 (November 25, 2020): 88–96. http://dx.doi.org/10.14445/23500301/ijap-v7i3p114.
Full text
13
Wang, Xijia. "New Explanation on Essence of Quantum Phenomena and Interactions and the Gravitational Action in Cosmic Continuum Theory." International Journal of Applied Physics 7, no. 3 (November 25, 2020): 88–96. http://dx.doi.org/10.14445/23500301/ijap-v7i3p114.
Full text
14
COOPERSTOCK, F. I. "THE CASE FOR UNQUANTIZED GRAVITY." International Journal of Modern Physics D 14, no. 12 (December 2005): 2207–11. http://dx.doi.org/10.1142/s0218271805008029.
Full textAbstract:
In this essay, we explore the hypothesis that gravity is best viewed as a non-quantized field, at least not in the usual sense of being quantized. It is linked to the energy localization hypothesis that energy, including the contribution from gravity, is localized in the region of the energy–momentum tensor. Evidence is gathered from among other aspects, the peculiar nature of gravitational plane waves and indirectly from the fact that there are no experimental results that point to a necessity for quantization. Should this hypothesis prove to be correct, it would favor the negation of the very existence of gravitons since gravitational waves would be seen as purely classical general relativistic constructs which carry no energy. Most significantly, unquantized gravity would turn the evidently unsolvable cosmological constant problem, viewed by various experts as the major crisis of modern physics, into a non-problem. In spite of this, there are indications to suggest that the study of limiting properties will lead to new insights into both the essence of space–time and the quantum world.
15
Chang, Yuan-Hann. "Alpha Magnetic Spectrometer (AMS) Releases New Results on Dark Matter Detection." Asia Pacific Physics Newsletter 04, no. 01 (October 23, 2015): 28–30. http://dx.doi.org/10.1142/s2251158x15000090.
Full textAbstract:
It is known that the majority (about 80%) of the matter in the universe is not visible, but rather a hypothetical "Dark Matter". The existence of Dark Matter has been postulated to explain the discrepancies between the estimated mass of visible matters in the galaxies, and their gravitational effects. Although it has been postulated for over 70 years, and has been commonly accepted by most scientists, the essence of the Dark Matter has not yet been understood. In particular, we still do not know what constitutes the Dark Matter. Direct detection of the Dark Matter is therefore one of the most important issues in physics.
16
Møller, P., and L. Christensen. "Metallicity has followed local gravitational potential of galaxies since z = 3." Monthly Notices of the Royal Astronomical Society 492, no. 4 (January 15, 2020): 4805–18. http://dx.doi.org/10.1093/mnras/staa128.
Full textAbstract:
ABSTRACT The MZ relation between stellar mass (M*) and metallicity (Z) of nearby galaxies has been described as both a global and local property, i.e. valid also on sub-galaxy scales. Here, we show that Z has remained a local property, following the gravitational potential, since z = 3. In absorption, the MZ relation has been well studied, and was in place already at z = 5.1. A recent absorption study of gamma-ray burst galaxies revealed a close match to damped Lyα (DLA) galaxies, surprising due to their vastly different impact parameters and leading the authors to suggest that local metallicity follows the local gravitational potential. In this paper, we formulate an observational test of this hypothesis. The test, in essence, forms a prediction that the velocity dispersion of the absorbing gas in galaxy haloes, normalized by the central velocity dispersion, must follow a steep log scale slope of −0.015 dex $\rm kpc^{-1}$ as a function of impact parameter out to at least 20–30 kpc. We then compile an archival data and literature-based sample of galaxies seen in both emission and absorption suitable for the test, and find that current data confirm the hypothesis out to 40–60 kpc. In addition, we show that the distribution of the velocity offsets between zem and zabs favours a model where DLA systems are composed of individual sub-clouds distributed along the entire path through the halo, and disfavours a model where they are one single cloud with a bulk motion and internal sub-structure.
17
ZHAO, HONGSHENG. "CONSTRAINING TEVES GRAVITY AS EFFECTIVE DARK MATTER AND DARK ENERGY." International Journal of Modern Physics D 16, no. 12a (December 2007): 2055–63. http://dx.doi.org/10.1142/s0218271807011759.
Full textAbstract:
The phenomena customarily described with the standard ΛCDM model are broadly reproduced by an extremely simple model in TeVeS, Bekenstein's1 modification of general relativity motivated by galaxy phenomenology. Our model can account for the acceleration of the Universe seen at SNeIa distances without a cosmological constant, and the accelerations seen in rotation curves of nearby spiral galaxies and gravitational lensing of high-redshift elliptical galaxies without cold dark matter. The model is consistent with BBN and the neutrino mass between 0.05 eV to 2 eV. The TeVeS scalar field is shown to play the effective dual roles of dark matter and dark energy, with the amplitudes of the effects controlled by a μ function of the scalar field, called the μ essence here. We also discuss outliers to the theory's predictions on multiimaged galaxy lenses and outliers on the subgalaxy scale.
18
Borvák, Levente, Attila Mészáros, and Jakub Řípa. "The analogy of K-correction in the topic of gamma-ray bursts." Proceedings of the International Astronomical Union 14, S346 (August 2018): 380–82. http://dx.doi.org/10.1017/s1743921318008025.
Full textAbstract:
AbstractIt is well-known that there are two types of gamma-ray bursts (GRBs): short/hard and long/soft ones, respectively. The long GRBs are coupled to supernovae, but the short ones are associated with the so called macronovae (also known as kilonovae), which can serve as the sources of gravitational waves as well. The kilonovae can arise from the merging of two neutron-stars. The neutron stars can be substituded by more massive black holes as well. Hence, the topic of gamma-ray bursts (mainly the topic of short ones) and the topic of massive binaries, are strongly connected.In this contribution, the redshifts of GRBs are studied. The surprising result - namely that the apparently fainter GRBs can be in average at smaller distances - is discussed again. In essence, the results of Mészáros et al. (2011) are studied again using newer samples of GRBs. The former result is confirmed by the newer data.
19
Guendelman, Eduardo, Emil Nissimov, and Svetlana Pacheva. "Vacuum structure and gravitational bags produced by metric-independent space–time volume-form dynamics." International Journal of Modern Physics A 30, no. 22 (August 5, 2015): 1550133. http://dx.doi.org/10.1142/s0217751x1550133x.
Full textAbstract:
We propose a new class of gravity-matter theories, describing [Formula: see text] gravity interacting with a nonstandard nonlinear gauge field system and a scalar “dilaton,” formulated in terms of two different non-Riemannian volume-forms (generally covariant integration measure densities) on the underlying space–time manifold, which are independent of the Riemannian metric. The nonlinear gauge field system contains a square-root [Formula: see text] of the standard Maxwell Lagrangian which is known to describe charge confinement in flat space–time. The initial new gravity-matter model is invariant under global Weyl-scale symmetry which undergoes a spontaneous breakdown upon integration of the non-Riemannian volume-form degrees of freedom. In the physical Einstein frame we obtain an effective matter-gauge-field Lagrangian of “k-essence” type with quadratic dependence on the scalar “dilaton” field kinetic term [Formula: see text], with a remarkable effective scalar potential possessing two infinitely large flat regions as well as with nontrivial effective gauge coupling constants running with the “dilaton” [Formula: see text]. Corresponding to each of the two flat regions we find “vacuum” configurations of the following types: (i) [Formula: see text] and a nonzero gauge field vacuum [Formula: see text], which corresponds to a charge confining phase; (ii) [Formula: see text] (“kinetic vacuum”) and ordinary gauge field vacuum [Formula: see text] which supports confinement-free charge dynamics. In one of the flat regions of the effective scalar potential we also find: (iii) [Formula: see text] (“kinetic vacuum”) and a nonzero gauge field vacuum [Formula: see text], which again corresponds to a charge confining phase. In all three cases, the space–time metric is de Sitter or Schwarzschild–de Sitter. Both “kinetic vacuums” (ii) and (iii) can exist only within a finite-volume space region below a de Sitter horizon. Extension to the whole space requires matching the latter with the exterior region with a nonstandard Reissner–Nordström–de Sitter geometry carrying an additional constant radial background electric field. As a result, we obtain two classes of gravitational bag-like configurations with properties, which on one hand partially parallel some of the properties of the solitonic “constituent quark” model and, on the other hand, partially mimic some of the properties of MIT bags in QCD phenomenology.
20
AL-SULAIM, MESAAD IBRAHIM. "ESTIMATION OF TRADE AND ECONOMIC RELATIONS BETWEEN THE KINGDOM OF SAUDI ARABIA AND AZERBAIJAN." Economic innovations 22, no. 3(76) (September 20, 2020): 76–86. http://dx.doi.org/10.31520/ei.2020.22.3(76).76-86.
Full textAbstract:
Topicality.Trade is the most important tool of the world economy in terms of building ties between countries, strengthening their interaction in the international exchange of goods, services and intellectual labor products. Aim and tasks. The purpose of the article is to estimate trade and economic relations between the Kingdom of Saudi Arabia and Azerbaijan, to prove having correlations between basic economic variables. Research results.The macro, micro and institutional factors affecting trade are initially classified and in separately explained in the article. Moreover, all economic indicators influencing exports have been analyzed in detail. The international experience on the estimation of foreign trade potential has been then investigated, it is pointed out that there are several models considering available, but the most suitable for research is the gravity model. The essence of the gravitational model is explained and the economic literature is studied to determine its application mechanism. On the basis of the gravity model, the trade relations of Saudi Arabia and Azerbaijan have been estimated by the method of the least squares of econometrics. Thus, two models have been set up initially with the variables of export of Saudi Arabia and Azerbaijan. One of variables is real exchange rate and this variable for each country has been calculated and added to the models by years. Conclusion.The features characterizing the adequacy of these models have been analyzed by using the e-views software package. So that, seasonal adjustment, their stationary, heteroschedasticity/homoscedasticity, the ratio of determination, autocorrelation have been analyzed. The models have been adjusted accordingly depending on the test results. The results have been interpreted on the basis of coefficients and their economic essence has been analyzed. It has been proved that there are positive trade correlations between two countries. In the conclusion, a summary of research has been noted.
21
Yu, Hang, Brian Seymour, Yijun Wang, and Yanbei Chen. "Uncertainty and Bias of Cosmology and Astrophysical Population Model from Statistical Dark Sirens." Astrophysical Journal 941, no. 2 (December 1, 2022): 174. http://dx.doi.org/10.3847/1538-4357/ac9da0.
Full textAbstract:
Abstract Gravitational-wave (GW) radiation from a coalescing compact binary is a standard siren, as the luminosity distance of each event can be directly measured from the amplitude of the signal. One possibility to constrain cosmology using the GW siren is to perform statistical inference on a population of binary black hole (BBH) events. In essence, this statistical method can be viewed as follows. We can modify the shape of the distribution of observed BBH events by changing the cosmological parameters until it eventually matches the distribution constructed from an astrophysical population model, thereby allowing us to determine the cosmological parameters. In this work, we derive the Cramér–Rao bound for both cosmological parameters and those governing the astrophysical population model from this statistical dark siren method by examining the Fisher information contained in the event distribution. Our study provides analytical insights and enables fast yet accurate estimations of the statistical accuracy of dark siren cosmology. Furthermore, we consider the bias in cosmology due to unmodeled substructures in the merger rate and mass distribution. We find that a 1% deviation in the astrophysical model can lead to a more than 1% error in the Hubble constant. This could limit the accuracy of dark siren cosmology when there are more than 104 BBH events detected.
22
Thomas Baby, Kappalumakkel. "The Skylark: A Symbol of Poetic Inspiration for Generations with Special Reference to Shelley and Hughes." Pertanika Journal of Social Sciences and Humanities 30, no. 2 (June 15, 2022): 723–42. http://dx.doi.org/10.47836/pjssh.30.2.16.
Full textAbstract:
The skylark is a tiny brown bird with a small crest on its head. It is slightly larger than a sparrow and is popularly known for its uninterrupted song during its upward flight. The bird is found in most parts of England and many European countries. A closer examination of English poetic tradition reveals that several English poets have anthologised this tiny bird, including famous poets such as Wordsworth, Shelley, Hopkins, Meredith, Rossetti, Rosenberg, and C Day-Lewis. The late poet laureate Ted Hughes also wrote about the skylark in our times. Even Shakespeare and Goethe have eulogised the skylark in their plays. Since Thomas Hardy has written a poem about ‘Shelley’s skylark,’ it is evident that traditionally ‘To a Skylark’ by Shelley is the most popular of all ‘Skylark’ poems. However, Hughes’s poem on skylark merits our attention because it is entirely different from the general trend of all other skylark poems written until his time. Therefore, this study explores how the skylark became a symbol of poetic inspiration for different generations of poets by analysing the two famous poems on skylark written by Shelley (1792–1822) and Hughes (1930–1998). While Shelley depicts the skylark as a pure spirit of joy, Hughes considers it an embodiment of cosmic energy resulting from the bird’s struggle for flight against the earth’s gravitational pull. Therefore, the different perceptions of Shelley and Hughes about the skylark constitute the essence of this discourse.
23
Makarieva, A. M., and V. G. Gorshkov. "Biotic pump of atmospheric moisture as driver of the hydrological cycle on land." Hydrology and Earth System Sciences Discussions 3, no. 4 (August 30, 2006): 2621–73. http://dx.doi.org/10.5194/hessd-3-2621-2006.
Full textAbstract:
Abstract. In this paper the basic geophysical and ecological principles are jointly analyzed that allow the landmasses of Earth to remain moistened sufficiently for terrestrial life to be possible. 1. Under gravity, land inevitably loses water to the ocean. To keep land moistened, the gravitational water runoff must be continuously compensated by the atmospheric ocean-to-land moisture transport. Using data for five terrestrial transects of the International Geosphere Biosphere Program we show that the mean distance to which the passive geophysical air fluxes can transport moisture over non-forested areas, does not exceed several hundred kilometers; precipitation decreases exponentially with distance from the ocean. 2. In contrast, precipitation over extensive natural forests does not depend on the distance from the ocean along several thousand kilometers, as illustrated for the Amazon and Yenisey river basins and Equatorial Africa. This points to the existence of an active biotic pump transporting atmospheric moisture inland from the ocean. 3. Physical principles of the biotic moisture pump are investigated based on the previously unstudied properties of atmospheric water vapor, which can be either in or out of hydrostatic equilibrium depending on the lapse rate of air temperature. A novel physical principle is formulated according to which the low-level air moves from areas with weak evaporation to areas with more intensive evaporation. Due to the high leaf area index, natural forests maintain high transpiration fluxes, which support the ascending air motion over the forest and "suck in" moist air from the ocean, which is the essence of the biotic pump of atmospheric moisture. In the result, the gravitational runoff water losses from the optimally moistened forest soil can be fully compensated by the biotically enhanced precipitation at any distance from the ocean. 4. It is discussed how a continent-scale biotic water pump mechanism could be produced by natural selection acting on individual trees. 5. Replacement of the natural forest cover by a low leaf index vegetation leads to an up to tenfold reduction in mean continental precipitation and runoff, in contrast to the previously available estimates made without accounting for the biotic moisture pump. The analyzed body of evidence testifies that the long-term stability of an intense terrestrial water cycle is unachievable without the recovery of natural, self-sustaining forests on continent-wide areas.
24
Makarieva, A. M., and V. G. Gorshkov. "Biotic pump of atmospheric moisture as driver of the hydrological cycle on land." Hydrology and Earth System Sciences 11, no. 2 (March 27, 2007): 1013–33. http://dx.doi.org/10.5194/hess-11-1013-2007.
Full textAbstract:
Abstract. In this paper the basic geophysical and ecological principles are jointly analyzed that allow the landmasses of Earth to remain moistened sufficiently for terrestrial life to be possible. 1. Under gravity, land inevitably loses water to the ocean. To keep land moistened, the gravitational water runoff must be continuously compensated by the atmospheric ocean-to-land moisture transport. Using data for five terrestrial transects of the International Geosphere Biosphere Program we show that the mean distance to which air fluxes can transport moisture over non-forested areas, does not exceed several hundred kilometers; precipitation decreases exponentially with distance from the ocean. 2. In contrast, precipitation over extensive natural forests does not depend on the distance from the ocean along several thousand kilometers, as illustrated for the Amazon and Yenisey river basins and Equatorial Africa. This points to the existence of an active biotic pump transporting atmospheric moisture inland from the ocean. 3. Physical principles of the biotic moisture pump are investigated based on the previously unstudied properties of atmospheric water vapor, which can be either in or out of aerostatic equilibrium depending on the lapse rate of air temperature. A novel physical principle is formulated according to which the low-level air moves from areas with weak evaporation to areas with more intensive evaporation. Due to the high leaf area index, natural forests maintain high evaporation fluxes, which support the ascending air motion over the forest and "suck in" moist air from the ocean, which is the essence of the biotic pump of atmospheric moisture. In the result, the gravitational runoff water losses from the optimally moistened forest soil can be fully compensated by the biotically enhanced precipitation at any distance from the ocean. 4. It is discussed how a continent-scale biotic water pump mechanism could be produced by natural selection acting on individual trees. 5. Replacement of the natural forest cover by a low leaf index vegetation leads to an up to tenfold reduction in the mean continental precipitation and runoff, in contrast to the previously available estimates made without accounting for the biotic moisture pump. The analyzed body of evidence testifies that the long-term stability of an intense terrestrial water cycle is unachievable without the recovery of natural, self-sustaining forests on continent-wide areas.
25
Abe, Oyeniyi, and Sewagegnehu D. Taye. "The ‘Flexibility’ Standard in the African Union and Its Ramification for the Implementation of the African Continental Free Trade Area (AfCFTA) Agreement." Global Trade and Customs Journal 16, Issue 2 (January 1, 2021): 80–91. http://dx.doi.org/10.54648/gtcj2021009.
Full textAbstract:
African Union’s (AU’s) integration history indicates that the continental body is plagued by flexibility hindering its goal of continental unity. This article investigates the utility of ‘flexibility’ standard in the adoption, ratification, and the implementation of AU treaties. Through an empirical analysis of the seventy treaties currently in force at the AU, thirty-four treaties have been able to secure the minimum level of ratification. Results show that a treaty that lacks the required number of signatories and ratifications creates a big challenge for the continental body. On the other hand, treaty ratification is not a guarantee for successful implementation. Historically, differing views on AU’s role, goals and effect on regional stability has forced a gravitational pull on the essence of the body. Yet, AU continues to facilitate regional free trade agreements and customs union. One of these is the recent African Continental Free Trade Area (AfCFTA) Agreement. This article argues that achieving flexibility under AfCFTA is illusionary, hence AU should strive towards attaining a clear roadmap for flexibility milieu in the implementation of AfCFTA. We argue that, for AfCFTA to be effective, all AU Member States must ratify the agreement, thereby ensuring the harmonization of regional trade agreements, and elimination of tariff and non-tariff barriers. The article concludes that the AU must utilize the principle of variable geometry to have a differentiated level and speed of integration, still achieving the same objective of a unified continent towards maximum intra-trade realization. flexibility, African Union, AfCFTA, variable geometry, regional integration, trade barriers, and trade liberalization
26
Xie, Qibin. "The Conjecture of the Essence of Gravitation." Journal of Physics: Conference Series 2002, no. 1 (August 1, 2021): 012052. http://dx.doi.org/10.1088/1742-6596/2002/1/012052.
Full text
27
Sologaev, V. I. "Use of filtration and electricity analogy in simulation of underflooding protection in urban construction." Russian Automobile and Highway Industry Journal 18, no. 4 (September 17, 2021): 450–62. http://dx.doi.org/10.26518/2071-7296-2021-18-4-450-462.
Full textAbstract:
Introduction. The fight against underflooding remains an urgent problem. The application of the analogy between water filtration and electric current has the goal of protecting the environment, built-up areas and, in particular, highways in cities from underflooding. Writing Ohm’s law similarly to Darcy’s filtration law, we achieve a better match to their analogy. This, in turn, makes it possible to develop new technologies for protection against underflooding in urban construction, for example, electroosmotic dewatering and its modeling. Such technologies make it possible to drain clayey soils.Methods and materials. Darcy’s law, Ohm’s law and the law of electroosmotic filtration are considered together. A methodology for modelling construction dewatering is given, taking into account the combined effect of the two physical laws of water filtration and electroosmosis, optimally combining the high-altitude geometric arrangement of drainage bases and contact electrodes. The options for draining clay soil under the action of an electric field are presented. With the combined use of gravitational forces and electric direct current forces in the drained soil, the total filtration rate is the sum of the Darcy’s law component and another component of the water velocity – electroosmotic filtration. An additional feature of joint modelling in a porous medium of water filtration and electroosmosis is that the mass of the water-resistant part of the soil and its part related to the dielectric may not coincide. This complexity of the model is overcome by dividing it into modules, which can then be combined in compliance with the balance principle, stitching modules along the boundaries. To continue the scientific discussion, a short but informative overview of international publications on the topic under consideration is given.Discussion. The methodology for complex calculation and modelling of the joint processes of water filtration in soils, the flow of electric current and electroosmotic filtration can find useful application in the development of effective protection against underflooding in urban construction. a sequence of algorithmic modelling steps is recommended. initially, it is recommended to run rough spreadsheet simulations on personal computers and mobile phones. next, a different modelling approach should be applied. based on the initial rough models of the previous step, it is necessary to write the algorithms in the programming language. the compiled model of the investigated filtration and electroosmosis processes will significantly increase the reliability of the design of protection against underflooding.conclusion. a comparison is made of the joint use of construction dewatering means of different physical essence, with simultaneous processes of gravitational filtration of underground water and passing a direct electric current through the drained soil, which causes an additional effect of electroosmosis. it is proposed to apply in a new way the analogy of water filtration and electric current in order to achieve more effective results of engineering activities by modeling protection against underflooding of building areas, ensuring the safety of urban construction when the level of groundwater rises.
28
Serge, Timashev. "The Planck Numbers and the Essence of Gravitation: Phenomenology." International Journal of Astrophysics and Space Science 5, no. 2 (2017): 19. http://dx.doi.org/10.11648/j.ijass.20170502.11.
Full text
29
Myrzakul, S. R., Y. M. Myrzakulov, and М. Arzimbetova. "INFLATION IN F(R, T) GRAVITATION WITH f-ESSENCE." PHYSICO-MATHEMATICAL SERIES 5, no. 333 (October 15, 2020): 106–12. http://dx.doi.org/10.32014/2020.2518-1726.89.
Full textAbstract:
. Modified theories of gravity have become a kind of paradigm in modern physics because they seem to solve several shortcomings of the standard General Theory of Relativity (GTR) related to cosmology, astrophysics and quantum field theory. The most famous modified theories of gravity are F(R) and F(T) theories of gravity. A generalization of these two modified theories and gravitations, which was first proposed by Myrzakulov Ratbay. In this paper, we study an inhomogeneous isotropic cosmological model with a fermion field f-essence whose action has the form , where R is the scalar of curvature, and T is the torsion scalar, and Lm is the Lagrangian f-essence. A particular case is studied in detail when parameters are obtained that describe the current accelerated expansion of the Universe. The type of Lagrangian f-essence of this model is determined. The presented results show that gravity with f-essence can describe inflation in the early evolution of the Universe. A modified F(R, T) gravity with f-essence is considered. Equations of motion were obtained and the inflationary period of the early Universe was considered. To describe the inflationary period, the form of the Hubble parameter and the slow-roll parameter were determined.
30
Ostrovsky, Anatoliy. "IMPROVEMENT OF RESCUE OPERATION WHEN POSTING GRINDING BALLS INTO A DIGGER." ENGINEERING, ENERGY, TRANSPORT AIC, no. 3(114) (September 28, 2021): 91–97. http://dx.doi.org/10.37128/2520-6168-2021-3-10.
Full textAbstract:
A characteristic feature of modern industries is the steady growth of mechanization and automation of production processes. The economic and social significance of mechanization is manifested in a wide range of measures aimed at replacing manual labor with machines and mechanisms, the transition to higher levels of mechanization, and ultimately to the highest degree of mechanization of automation. The combined development of science and technology significantly affects both complex and partial (non-complex) mechanization of production processes, generating an increase in the number of parts. A significant place in the technology of manufacturing parts is the casting process. About half of the parts are made of molten metals and other materials. One of the common methods is die casting. Shells (molds) of metal or cast iron molds, for free (gravitational) filling with liquid metal, are used repeatedly. Detachable and non-removable (solid) molds are used. The opening surface of the detachable mold can be horizontal, vertical, or combined. The subject of the study is a mold, which consists of two half-shapes with a vertical opening surface and pins of mutual centering of the shells. A wide range of enterprises: mining and processing plants, cement plants, construction plants, energy generating companies, etc. use the products of casting in the mold grinding layers. All types and sizes of grinding layers are intended for grinding of raw materials. Due to various technical reasons, during casting, a metal film is formed near the grinding balls, which fills the entire surface of the opening of the detachable mold. The operation of removing the lattice from the grinding layers is necessary to reproduce the geometric shape, quality requirements and considerations of industrial aesthetics of the product. Performing such an additional operation requires the collective work of employees with the use of physical force and appropriate tools. Existing technology with the use of metalwork tools leads to a deterioration in the appearance of the layers, and sometimes to damage the products. The essence of improving the lattice operation is to use a specially designed device for this operation, which in turn creates the conditions for mechanization of the production of grinding balls.
31
Chugreev, Yu V. "The k-Essence in the Relativistic Theory of Gravitation and General Relativity." Theoretical and Mathematical Physics 194, no. 3 (March 2018): 439–49. http://dx.doi.org/10.1134/s0040577918030108.
Full text
32
Borowski, Tomasz. "Actual Picture of the Law of Universal Gravitation and the Quantum Gravity Theory Describing the Real State of the Universe." International Letters of Chemistry, Physics and Astronomy 16 (September 2013): 44–53. http://dx.doi.org/10.18052/www.scipress.com/ilcpa.16.44.
Full textAbstract:
This paper presents the real sense of the classical and quantum theory of gravitation as a component of the actual picture of the universe where the volume, as the size of the expanding universe, approaches infinity, while the total of material masses goes to zero. At present, these two standard theories describe the phenomenon of gravitation but do not explain the very mechanism and the cause of this process. This constant and real lack of information on that subject is consistent with natural laws and the same with the laws of physics, which were already experimentally determined by Werner Heisenberg in 1927. The paper also presents the causes of inability to explain up to the present the actual picture of the essence of the universe.
33
Borowski, Tomasz. "Actual Picture of the Law of Universal Gravitation and the Quantum Gravity Theory Describing the Real State of the Universe." International Letters of Chemistry, Physics and Astronomy 16 (August 5, 2013): 44–53. http://dx.doi.org/10.56431/p-3vqq76.
Full textAbstract:
This paper presents the real sense of the classical and quantum theory of gravitation as a component of the actual picture of the universe where the volume, as the size of the expanding universe, approaches infinity, while the total of material masses goes to zero. At present, these two standard theories describe the phenomenon of gravitation but do not explain the very mechanism and the cause of this process. This constant and real lack of information on that subject is consistent with natural laws and the same with the laws of physics, which were already experimentally determined by Werner Heisenberg in 1927. The paper also presents the causes of inability to explain up to the present the actual picture of the essence of the universe.
34
Pavlenko, Yu. "GRAVITY: THEORETICAL MODEL." TRANSBAIKAL STATE UNIVERSITY JOURNAL 28, no. 5 (2022): 120–29. http://dx.doi.org/10.21209/2227-9245-2022-28-5-120-129.
Full textAbstract:
A theoretical model of the formation of gravity and such dialectical categories as time, speed of light and intranuclear superdense matter, directly related to it, are presented. Categories are forms of knowledge reflection about the universal laws of the objective world, its unity, interaction and development of its components. Gravity is the main creative derivative of the potential energy of the Universe. This is a product of the process of interference of quantum wave fluctuations of potential energy and coherent wave oscillations of the quark-gluon energy mechanism of atomic nuclei. The consequence of the most complex microwave interaction between the potential energy consumed by nuclei and the internal energy of atomic nuclei are ultrashort waves, representing electromagnetic γ-radiation (γ-quantum, photon, corpuscle). In areas of increased concentration of wave energy, when the anomalous threshold oscillation frequency of 734 Hz is reached, the interaction of locally manifested wave processes of quantum fluctuation and interference can form elementary particles with a dense mass, increased energy charge and other characteristics characteristic of baryonic matter. The frequency of 734 Hz, indistinguishable by man, corresponds to the time interval of 0.00136 seconds and the supposed boundary of the pulsating material Universe. Electromagnetic and gravitational radiations are actively formed on it, entropy and products of other energy processes corresponding to the bifurcation boundary of evolution decrease or increase. The relevance of the research lies in the expediency of systematics, structuring, systematization of fundamental knowledge about matter, its "origins" to clarify the methodological principles and the significance of the "original" energy evolution in natural science. The object of the research is gravity - one of the most important methodological categories in the form of fundamental time. The subject of the research is the fundamental properties of gravity, which ensure the existence and evolution of the matter of the Metagalaxy. The purpose of the research is virtual forms of the existence and evolution of gravity, and the main task to be solved is to clarify the significance of the wave quantum fluctuation of energy. The methodological tool for solving the problem is the numerous fundamental structural levels of the organization of the matter of the Universe, indicating its polygenic energy essence and evolutionary nature. The concept of a system of scientifically based, interconnected and logically linked scientific views based on many years of experience in small-medium-scale predictive studies in the oldest mining region of Russia - Eastern Transbaikalia. Encyclopedic natural-science knowledge of the matter of the Universe, fundamental hierarchical structures of its matter, cause-and-effect relationships of the functioning of energy systems, theoretical and practical models of the Earth's matter, as well as knowledge of the objective perception of the world, its laws and phenomena by collecting, computer processing of empirical data to solve the problem are used. . It is taken into account that dialectical materialism beyond the "visibility" (length) of light (optical) and electron waves is gradually being replaced by theoretical (philosophical) materialism based on the laws of logic and fractal. Gravity combines space and time into a single energy category called the Universe
35
Aygün, Sezgin. "Various dark energy models with time-varying G and Λ in f(R, T) gravitation theory." Modern Physics Letters A 34, no. 34 (November 5, 2019): 1950280. http://dx.doi.org/10.1142/s0217732319502808.
Full textAbstract:
In this research, we have investigated tachyon and [Formula: see text]-essence dark energy (DE) candidates with varying [Formula: see text] and [Formula: see text] for Marder universe in [Formula: see text] gravitation theory [Harko et al., Phys. Rev. D 84, 024020 (2011)]. Here, [Formula: see text] is the arbitrary function of Ricci scalar ([Formula: see text]) and the trace of [Formula: see text]. To solve [Formula: see text] gravity field equations, three different approximations have been used such as cosmological term, equation of state (EoS) parameter and the anisotropy feature of Marder universe. Also, we have discussed some physical results with various graphics.
36
Surendra Singh, S., K. Manihar Singh, and Leishingam Kumrah. "Kaluza–Klein Universe interacting with wet dark fluid in f(R,T) gravity." International Journal of Modern Physics A 36, no. 07 (March 10, 2021): 2150043. http://dx.doi.org/10.1142/s0217751x21500433.
Full textAbstract:
In this paper, we study the essence of [Formula: see text] gravitation theory in five-dimensional Universe and see the role of dark energy in the form of wet dark fluid in a Kaluza–Klein Universe. It is found that the dark energy is not exaggerated in contributing to the accelerating expansion of the Universe though the expansion is inherent as a result of the theory itself and due to the geometric contribution of matter. It is interesting to see that in some model it is found that there was some era before the beginning of the present era. Some of the models are seen to go to [Formula: see text]CDM models in late future as in Einstein gravitation theory, starting the evolution with a big bang. Most of the models undergo early inflation as well as late-time accelerating expansion thus defining as good models for real astrophysical situations, with dark energy playing fundamental role in these Universe. Most interesting observation from this investigation is that we can developed new isotropic and anisotropic models of Kaluza–Klein Universe.
37
Aktaş, Can. "Various dark energy models for variables G and Λ in f(R, T) modified theory." Modern Physics Letters A 34, no. 13 (April 30, 2019): 1950098. http://dx.doi.org/10.1142/s0217732319500986.
Full textAbstract:
In this paper, we have researched tachyon field, k-essence and quintessence dark energy (DE) models for Friedmann–Robertson–Walker (FRW) universe with varying G and [Formula: see text] in f(R, T) gravitation theory. The theory of f(R, T) is proposed by Harko et al. [Phys. Rev. D 84, 024020, 2011]. In this theory, R is the Ricci scalar and T is the trace of energy–momentum tensor. For the solutions of field equations, we have used linearly varying deceleration parameter (LVDP), the equation of state (EoS) and the ratio between [Formula: see text] and Hubble parameter. Also, we have discussed some physical behavior of the models with various graphics.
38
Ermolin, Evgeniy A. "Autofiction as a media stratagem." Verhnevolzhski Philological Bulletin 2, no. 29 (2022): 71–79. http://dx.doi.org/10.20323/2499-9679-2022-2-29-71-79.
Full textAbstract:
The article deals with the phenomenon of autofiction, characteristic of modern culture, as a reflex of mental procedures and a creative stratagem related to a person's orientation in the modern world, as applied to the latest media practices and journalistic self-realization. Its presence is determined by the fundamental features of culture, the way of self-perception and self-determination of a modern person in the context of Postmodern culture. Autofiction is implemented both in literature and as a media practice, a phenomenon of modern journalism. Journalistic gravitation toward storytelling, an emphasis on authorship,on personal journalism and transparent blogging correlate with the practices of autofiction as a radical self-presentation of the individual in modern narrative discourse. At the same time, autofiction is as much a solution to the personal problems and difficulties of the contemporary author as it is a mere fixation of them, an evidence of their incomplete, inconclusive resolution. Autofiction exposes the difficulties of individual self-fixation. This is an attempt to give a little more significance to what it has in a small dose. Autofiction is associated with a special understanding of authenticity, it is alien to the traditional criteria of heroics and ethical integrity, which can be perceived as tools and means of alienation, as an unacceptable substitution of a personal essence for a given norm, a role in the society of a performance. Here emotions and feelings create the effect that enables us to consider what is happening to be credible. Autofiction is the author's self-comprehension within those limits that are defined for him/herself, identifying them with the limits of authenticity as he/she understands it, based on an attempt to find the elusive edge of personal presence in a shaky, fluid world.Autofiction displays a media tendency to recognize the legitimacy of fiction based on the general underlying logic of life revealed by the narrative. An essential question is the significance of the autofiction message, its public relevance, the response to the audience's expected agenda.
39
Akhoury, Ratindranath, David Garfinkle, and Ryo Saotome. "Gravitational collapse of k-essence." Journal of High Energy Physics 2011, no. 4 (April 2011). http://dx.doi.org/10.1007/jhep04(2011)096.
Full text
40
Manna, Goutam. "Gravitational collapse for the K-essence emergent Vaidya spacetime." European Physical Journal C 80, no. 9 (September 2020). http://dx.doi.org/10.1140/epjc/s10052-020-8383-y.
Full textAbstract:
AbstractIn this paper, we study the gravitational collapse in the k-essence emergent gravity using a generalized Vaidya-type metric as a background. We also analyze the cosmic censorship hypothesis for this system. We show that the emergent gravity metric resembles closely to the new type of the generalized Vaidya metrics for null fluid collapse with the k-essence emergent mass function, where we consider the k-essence scalar field being a function solely of the advanced or the retarded time. This new type of k-essence emergent Vaidya metric has satisfied the required energy conditions. The existence of the locally naked central singularity, the strength and the strongness of the singularities for the k-essence emergent Vaidya metric are the interesting outcomes of the present work.
41
Leonard, C. Danielle, Jonathan Ziprick, Gabor Kunstatter, and Robert B. Mann. "Gravitational collapse of K-essence matter in Painlevè-Gullstrand coordinates." Journal of High Energy Physics 2011, no. 10 (October 2011). http://dx.doi.org/10.1007/jhep10(2011)028.
Full text
42
Li, Huawang. "How Does Universal Gravitation Arise." Global Journal of Science Frontier Research, October 30, 2019, 21–30. http://dx.doi.org/10.34257/gjsfravol19is9pg21.
Full textAbstract:
Great principles are simple, and looking for the essence of physics requires us to trace the roots. Binary can be arranged to combine our information world, then would the three elementary particles [1] to form the periodic table of elements? Without giving them additional attributes (such as electricity, magnetism, gravity, etc.), would they further arranged this world? This paper proved the existence of a new particle through three physical experiments. The mass of this new particle is only 10-20 of the electron, and it is named Yizi. Through the discovery of Yizi, we will reveal the cause of gravitation and expound the essence of force. Experiment 1: The gravitational force between two objects is not only related to their masses but also their ambient temperature. The force between two objects is mutually exclusive when their temperature is lower than ambient. Experiment 2: Change the temperature of the big metal ball on the gravitation torsion scale, keeping the temperature of the small metal ball unchanged, and observe the force of the big ball on the small ball. Experiment 3: Under constant temperature and vacuum conditions, the temperature of an object is related to its mass. The greater its mass the higher its temperature.
43
Konoplya, Roman A., and Alexander Zhidenko. "Can the abyss swallow gravitational waves or why we do not observe echoes?" Europhysics Letters, May 9, 2022. http://dx.doi.org/10.1209/0295-5075/ac6e00.
Full textAbstract:
Abstract Here we propose a simple explanation why echoes from wormholes mimicking black holes may be so small that they cannot be observed. The essence of the effect is in the redistribution of the initial energy of gravitational wave among multiple universes, connected by a wormhole.
44
Venikoudis, S. A., K. V. Fasoulakos, and F. P. Fronimos. "Late-time Cosmology of scalar field assisted f(𝒢) gravity." International Journal of Modern Physics D 31, no. 05 (February 28, 2022). http://dx.doi.org/10.1142/s0218271822500389.
Full textAbstract:
In this work, we present the late-time behaviour of the universe in the context of Einstein–Gauss–Bonnet gravitational theory. The theory involves a scalar field, which represents low-effective quantum corrections, assisted by a function [Formula: see text] solely depending from the Gauss–Bonnet topological invariant [Formula: see text]. It is considered that the dark energy serves as the impact of all geometric terms, which are included in the gravitational action and the density of dark energy acts as a time-dependent cosmological constant evolving with an infinitesimal rate and driving the universe into an accelerating expansion. We examine two cosmological models of interest. The first involves a canonical scalar field in the presence of a scalar potential while the second, involves a scalar field which belongs to a generalized class of theories [Formula: see text] namely the k-essence scalar field in the absence of scalar potential. As it is proved, the aforementioned models are in consistency with the latest Planck data and in relatively good agreement with the [Formula: see text]CDM standard cosmological model. The absence of dark energy oscillations at the early stages of matter-dominated era, which appear in alternative scenarios of cosmological dynamics in the context of modified [Formula: see text] gravitational theories, indicates an advantage of the theory for the interpretation of late-time phenomenology.
45
Ganesh, S. "5-D thermal field theory, Einstein field equations and spontaneous symmetry breaking." Classical and Quantum Gravity, January 11, 2023. http://dx.doi.org/10.1088/1361-6382/acb24c.
Full textAbstract:
Abstract It has been shown previously, that the spatial thermal variation of a thermal medium can be recast as a variation in the Euclidean metric. It is now extended to temporal variations in temperature, for a non-relativistic thermal bath, which remains in local thermal equilibrium. This is achieved by examining the thermal field theory in a five-dimensional space-time-temperature. The bulk thermodynamic quantity, namely the energy density, is calculated for a neutral scalar field with a time-dependent Hamiltonian. Furthermore, the concept of recasting thermal variations as a variation in the metric is extended to thermal systems in a gravitational field. The Einstein field equations, in the 5-D space-time-temperature, is determined. It is shown that, if the scalar Lagrangian is non-minimally coupled with gravity, the resulting Ricci scalar can lead to spontaneous symmetry breaking, leading to the Higgs mechanism. In essence, the asymmetry in the distribution of temperature in space-time can translate to spontaneous symmetry breaking of particle fields, in a very strong gravitational field.
46
Manna, Goutam, Arijit Panda, Aninda Karmakar, Saibal Ray, and Md Rabiul Islam. "$f(\bar{R}, L(X))$-gravity in the context of dark energy with power law expansion and energy conditions." Chinese Physics C, November 3, 2022. http://dx.doi.org/10.1088/1674-1137/ac9fbe.
Full textAbstract:
Abstract The motto of this work is to generate a general formalism of $f(\bar{R}, L(X))-$gravity in the context of dark energy under the framework of the {\bf K-}essence emergent geometry with the Dirac-Born-Infeld (DBI) variety of action, where $\bar{R}$ is the familiar Ricci scalar, $L(X)$ is the DBI type non-canonical Lagrangian with $X={1\over 2}g^{\mu\nu}\nabla_{\mu}\phi\nabla_{\nu}\phi$ and $\phi$ is the {\bf K-}essence scalar field. The emergent gravity metric $\G_{\mu\nu}$ and the well known gravitational metric $g_{\mu\nu}$ are not conformally equivalent. We have constructed a modified field equation using the metric formalism in $f(\bar{R}, L(X))$-gravity incorporating the corresponding Friedmann equations in the framework of the background gravitational metric which is of Friedmann-Lema{\^i}tre-Robertson-Walker (FLRW) type. The solution of modified Friedmann equations have been deduced for the specific choice of $f(\bar{R}, L(X))$, which is of Starobinsky-type, using power law expansion method. The consistency of the model with the accelerating phase of the Universe has been shown, when we restrict ourselves to consider the value of the dark energy density, as $\dot\phi^{2}=\frac{8}{9}=0.888 <1$, which indicates that the present Universe is dark energy dominated. Graphical plots for the energy density ($\rho$), pressure ($p$) and equation of state parameter ($\o$) w.r.t. time ($t$) based on parametric values are interestingly consistent with the dark energy domination and hence accelerating features. We also put some light on the corresponding energy conditions and constraints of the $f(\bar{R}, L(X))$ theory with one basic example.
47
Fronimos, F. P., and S. A. Venikoudis. "Inflation with exotic kinetic terms in Einstein–Chern–Simons gravity." International Journal of Modern Physics A 36, no. 30 (October 30, 2021). http://dx.doi.org/10.1142/s0217751x21502298.
Full textAbstract:
An alternative scenario about the phenomenology of primordial universe is [Formula: see text]-inflation. According to this concept, inflation can be achieved by nonstandard kinetic term of scalar field, namely, the inflaton. In this paper, we focus on [Formula: see text]-essence models in the presence of a higher order and a linear kinetic term. Furthermore, the inflationary phenomenology with a Dirac–Born–Infeld scalar field is briefly examined, which arises from quantum theories of gravity such as superstring theory. Our approach about the inflationary era is that it can be described in the context of Einstein’s gravity involving quantum corrections such as the Chern–Simons string inspired parity violating gravitational term. The equations of motion namely, the Friedmann equation, the Raychadhuri equation and the Klein–Gordon equation for an expanding background are extracted from the gravitational action utilizing the variational principle. The consequential system of differential equations with respect to Hubble’s parameter and the inflaton field was quite perplexed in order to be solved with an analytic way. Therefore, the slow-roll conditions during inflationary era were imposed and terms with minor numerically contribution were neglected. From the overall phenomenological analysis, it is proved that models with exotic kinetic terms can generate viable results in consistency with the latest Planck data. Finally, the presence of Chern–Simons quantum corrections shifts the primordial spectral tensor index to blue. Even though blue gravitational waves are yet to be observed, if detected, compatibility with the aforementioned theory can be achieved.
48
Weinberg, Martin D., and Michael S. Petersen. "Using Multichannel Singular Spectrum Analysis to Study Galaxy Dynamics." Monthly Notices of the Royal Astronomical Society, December 26, 2020. http://dx.doi.org/10.1093/mnras/staa3997.
Full textAbstract:
Abstract N-body simulations provide most of our insight into the structure and evolution of galaxies, but our analyses of these are often heuristic and from simple statistics. We propose a method that discovers the dynamics in space and time together by finding the most correlated temporal signals in multiple time series of basis function expansion coefficients and any other data fields of interest. The method extracts the dominant trends in the spatial variation of the gravitational field along with any additional data fields through time. The mathematics of this method is known as multichannel singular spectrum analysis (M-SSA). In essence, M-SSA is a principal component analysis of the covariance of time series replicates, each lagged successively by some interval. The dominant principal component represents the trend that contains the largest fraction of the correlated signal. The next principal component is orthogonal to the first and contains the next largest fraction, and so on. Using a suite of previously analysed simulations, we find that M-SSA describes bar formation and evolution, including mode coupling and pattern-speed decay. We also analyse a new simulation tailored to study vertical oscillations of the bar using kinematic data. Additionally, and to our surprise, M-SSA uncovered some new dynamics in previously analysed simulations, underscoring the power of this new approach.
49
Kremen, Roman. "Space and Time." Vox. Philosophical journal, December 30, 2022. http://dx.doi.org/10.37769/2077-6608-2022-39-7.
Full textAbstract:
The genesis of space and time is investigated within the rotational-monadic paradigm. It is established that the essence of the phenomenon of space is revealed through the dialectical synthesis of its two aspects — ideal and material, where the material aspect is represented by the metaphysical construct of protomonad. It is shown that basic physical distinctions such as motion, mass, gravitation find a meaningful hermeneutic through the material aspect of space, which has a purely discrete structure, while the contradiction about finitude — infinity is resolved by juxtaposing metaphysical and ontic spaces, where the Universe is represented as an “egg”. The analysis of temporality is preceded by remarks on the relational and substantive concepts of time, consideration of the discreteness-continuity dilemma, and criticism of the absolutization of discreteness in the temporality representation. It is argued that discreteness and continuity are combined dialectical oppositions through which the temporal reality is actualized, where continuity is hidden from observation in the metaphysical world and discreteness is manifested explicitly in the physical world. Three dimensions of time — Present, Past and Future — are discussed, as a result of which it is stated that in the primary way time is found as an attribute of consciousness and only in the secondary way it correlates with phenomenological reality. New differentiations of time are revealed: interval Present, embracing as a universum other moduses of the Present, and two- component time in the form of cyclic and linear components which allow us to make a justified positive conclusion about the existence of transcendental subjectivity, being the basis of absolute temporality.