Bibliographies thématiques / Dark energy models

Littérature scientifique sur le sujet « Dark energy models »

Auteur : Grafiati
Publié le 18 mai 2024

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Articles de revues sur le sujet "Dark energy models"

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POLARSKI, DAVID. « DARK ENERGY ». International Journal of Modern Physics D 22, no 14 (décembre 2013) : 1330027. http://dx.doi.org/10.1142/s0218271813300279.

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Dark energy models account for the present accelerated expansion of the universe. Many models were suggested and investigated, based on very different physical principles. We will review some representative models emphasizing similarities and differences between these various approaches.
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Motta, Verónica, Miguel A. García-Aspeitia, Alberto Hernández-Almada, Juan Magaña et Tomás Verdugo. « Taxonomy of Dark Energy Models ». Universe 7, no 6 (26 mai 2021) : 163. http://dx.doi.org/10.3390/universe7060163.

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The accelerated expansion of the Universe is one of the main discoveries of the past decades, indicating the presence of an unknown component: the dark energy. Evidence of its presence is being gathered by a succession of observational experiments with increasing precision in its measurements. However, the most accepted model for explaining the dynamic of our Universe, the so-called Lambda cold dark matter, faces several problems related to the nature of such energy component. This has led to a growing exploration of alternative models attempting to solve those drawbacks. In this review, we briefly summarize the characteristics of a (non-exhaustive) list of dark energy models as well as some of the most used cosmological samples. Next, we discuss how to constrain each model’s parameters using observational data. Finally, we summarize the status of dark energy modeling.
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Khurshudyan, Martiros, et Asatur Khurshudyan. « Some Interacting Dark Energy Models ». Symmetry 10, no 11 (2 novembre 2018) : 577. http://dx.doi.org/10.3390/sym10110577.

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In this paper, we study various cosmological models involving new nonlinear forms of interaction between cold dark matter (DM) and dark energy (DE) assuming that DE is a barotropic fluid. The interactions are nonlinear either due to log ( ρ d e / ρ d m ) or log ( ρ d m / ρ d e ) parameterizations, respectively. The main purpose of this paper is to demonstrate the applicability of the forms of suggested interactions to the problem of modern cosmology known as accelerated expansion of the Universe. Using the differential age of old galaxies expressed in terms of H ( z ) data, the peak position of baryonic acoustic oscillations (known as BAO data), the SN Ia data with strong gravitational lensing data, we obtain the best fit values of the model parameters for each case. Besides, using O m analysis and S 3 parameter from the statefinder hierarchy analysis, we also demonstrate that the considered models are clearly different from the Λ CDM model. We obtain that the models predict Hubble parameter values consistent to the estimations from gravitational lensing, which probes the expansion out to z ≤ 1.7 . We show that, with considered models, we can also explain PLANCK 2015 and PLANCK 2018 experiment results.
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Tawfik, Abdel Nasser, et Eiman Abou El Dahab. « Review on Dark Energy Models ». Gravitation and Cosmology 25, no 2 (avril 2019) : 103–15. http://dx.doi.org/10.1134/s0202289319020154.

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Sahni, Varun, et Yuri Shtanov. « Braneworld models of dark energy ». Journal of Cosmology and Astroparticle Physics 2003, no 11 (24 novembre 2003) : 014. http://dx.doi.org/10.1088/1475-7516/2003/11/014.

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Sahni, Varun. « Theoretical models of dark energy ». Chaos, Solitons & ; Fractals 16, no 4 (mai 2003) : 527–37. http://dx.doi.org/10.1016/s0960-0779(02)00221-7.

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YOO, JAEWON, et YUKI WATANABE. « THEORETICAL MODELS OF DARK ENERGY ». International Journal of Modern Physics D 21, no 12 (novembre 2012) : 1230002. http://dx.doi.org/10.1142/s0218271812300029.

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Mounting observational data confirm that about 73% of the energy density consists of dark energy which is responsible for the current accelerated expansion of the Universe. We present observational evidences and dark energy projects. We then review various theoretical ideas that have been proposed to explain the origin of dark energy; they contain the cosmological constant, modified matter models, modified gravity models and the inhomogeneous model. The cosmological constant suffers from two major problems: one regarding fine-tuning and the other regarding coincidence. To solve them there arose modified matter models such as quintessence, k-essence, coupled dark energy and unified dark energy. We compare those models by presenting attractive aspects, new rising problems and possible solutions. Furthermore, we review modified gravity models that lead to late-time accelerated expansion without invoking a new form of dark energy; they contain f(R) gravity and the Dvali–Gabadadze–Porrati (DGP) model. We also discuss observational constraints on those models and on future modified gravity theories. Finally we review the inhomogeneous Lemaître–Tolman–Bondi (LTB) model that drops an assumption of the spatial homogeneity of the Universe. We also present basics of cosmology and scalar field theory, which are useful especially for students and novices to understand dark energy models.
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Chan, R., M. F. A. da Silva et Jaime F. Villas da Rocha. « Star models with dark energy ». General Relativity and Gravitation 41, no 8 (29 janvier 2009) : 1835–51. http://dx.doi.org/10.1007/s10714-008-0755-9.

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Arun, Kenath, S. B. Gudennavar, A. Prasad et C. Sivaram. « Alternate models to dark energy ». Advances in Space Research 61, no 1 (janvier 2018) : 567–70. http://dx.doi.org/10.1016/j.asr.2017.08.006.

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Pearson, Jonathan A. « Material models of dark energy ». Annalen der Physik 526, no 7-8 (10 juin 2014) : 318–39. http://dx.doi.org/10.1002/andp.201400052.

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Thèses sur le sujet "Dark energy models"

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Elmufti, Mohammed. « Perturbations of dark energy models ». Thesis, University of Western Cape, 2012. http://hdl.handle.net/11394/3386.

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>Magister Scientiae - MSc
The growth of structure in the Universe proceeds via the collapse of dark matter and baryons. This process is retarded by dark energy which drives an accelerated expansion of the late Universe. In this thesis we use cosmological perturbation theory to investigate structure formation for a particular class of dark energy models, i.e. interacting dark energy models. In these models there is a non-gravitational interaction between dark energy and dark matter, which alters the standard evolution (with non-interacting dark energy) of the Universe. We consider a simple form of the interaction where the energy exchange in the background is proportional to the dark energy density. We analyse the background dynamics to uncover the e ect of the interaction. Then we develop the perturbation equations that govern the evolution of density perturbations, peculiar velocities and the gravitational potential. We carefully account for the complex nature of the perturbed interaction, in particular for the momentum transfer in the dark sector. This leads to two di erent types of model, where the momentum exchange vanishes either in the dark matter rest-frame or the dark energy rest-frame. The evolution equations for the perturbations are solved numerically, to show how structure formation is altered by the interaction.
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Duran, Sancho Ivan. « Constraining Cosmological Models of Dark Energy ». Doctoral thesis, Universitat Autònoma de Barcelona, 2013. http://hdl.handle.net/10803/125917.

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Avui en dia, l'Univers sembla estar experimentant una fase d'expansió accelerada, com ho demostren les dades de supernoves i posteriorment corroborada per una sèrie de mesuraments cosmològiques -molt recentment pel satèl·lit Planck. Mentre que aquesta expansió pot ser descrit en la teoria de la gravetat d'Einstein mitjançant la invocació de l'existència d'una positiva, però extremadament petita constant cosmològica, Λ, connectat al buit quàntic, s'han proposat moltes alternatives. A grans trets, el contingut d'energia de l'univers actual es pot dividir en 5% de la matèria bariònica i el 95% d'un invisible (conegut com el "sector fosc", perquè els seus components no interactuen electromagnèticament), el 25% del qual constituït per matèria no-relativista, partícules massives d'interacció feble ("matèria fosca freda") i un 75% d'un component amb una enorme pressió negativa, l'anomenada "energia fosca". La naturalesa d'aquest últim component és completament desconegut, això justifica que s'han proposat molts candidats "de prova". De moment, la més simple i de més èxit és la constant cosmològica, esmentada anteriorment. No obstant això, pateix de dos inconvenients principals a nivell teòric: el problema de la coincidència i el problema del “fine-tunning”. L'objectiu d'aquesta memòria és proposar i ajustar els models cosmològics de l'energia fosca que eviten aquestes dificultats. Aquesta tesi està organitzada de la següent manera: Els capítols § 2, § 3 i § 4 s'introdueixen conceptes bàsics utilitzats en considerar els diferents models que conformen el nostre treball de recerca. Els següents capítols se centren en els diferents models cosmològics. Al § 5, l'energia fosca compleix el principi hologràfic i es postula que interactua (també sense gravetat) amb la matèria fosca. El principi hologràfic estableix una escala de longitud, en aquest cas la longitud d' Hubble, és a dir, la distància que limita els esdeveniments causalment connectats. Al capítol § 6, s'estudia amb més profunditat el model anterior, i es presenta una alternativa al mateix. Tots dos models comparteixen l'evolució fons idèntica però cada component es comporta de manera diferent, la qual cosa indueix un comportament divers quan es consideren les pertorbacions. Això permet discriminar observacionalment un model de l'altre. Un model d'energia fosca hologràfica més es proposa en el § 7, aquest amb l’escala de longitud determinada per el Radi de Ricci (és a dir, la mida màxima d'una pertorbació que condueix a un forat negre). Un cop més, es suposa una interacció no-gravitacional entre l'energia fosca i la matèria fosca. Al § 8, s'estudia un model unificat (amb una unificació entre la matèria fosca ad energia fosca) proposat anteriorment. Atès que l'espai de paràmetres que s'ajusta a les dades observacionals és molt petit (i també en vista del seu interès teòric), descomponem el component únic en matèria fosca freda i buit que interactuen entre ells. Com a conseqüència, l'espai de paràmetres permesos queda augmentada considerablement. Encara que els models esmentats anteriorment imiten a nivell de fons el model ΛCDM estàndard, els components foscos evolucionen de manera molt diferent. Per estudiar-los rigorosament, els codis numèrics de les pertorbacions cosmològiques han de ser adequadament modificats, amb l'inconvenient d'incrementar notablement el temps de càlcul. Aquest fet és alleujat al § 9, on un nou mètode per calcular l'espectre de potència dels models d'energia fosca és proposat. Finalment, en el § 10 tres noves parametritzacions del paràmetre de desacceleració, amb base a arguments termodinàmics sòlids, es proposen i es contrasta amb les dades observacionals.
Nowadays the Universe appears to be undergoing a phase of accelerated expansion, as witnessed by supernovae data and later corroborated by a host a cosmological measurements -very recently by the Planck satellite. While this expansion can be described in Einstein’s theory of gravity by invoking the existence of a positive but exceedingly small cosmological constant, Λ, connected to the quantum vacuum, many alternative, and sometimes sophisticated, explanations have been proposed. Roughly, the energy content of the present universe can be split into 5% of baryonic matter and 95% of a non-visible (dubbed the “dark sector” because its components do not interact electromagnetically) whose 25% consists of non-relativistic, weakly interacting massive particles (“cold dark matter”) and a 75% of a component with a huge negative pressure, the so-called “dark energy”. The nature of the latter component is completely unknown; this justifies that many “trial” candidates have been proposed. By far, the simplest and most successful one is the cosmological constant, mentioned above. However, it suffers from two main drawbacks at the theoretical level: the coincidence problem and the fine tuning problem. The aim of this Memoir is to propose and constrain cosmological models of dark energy that circumvent these difficulties. This Memoir is organized as follows: The Chapters §2, §3 and §4 introduce basic concepts widely used when considering the different models that conforms our research work. The following Chapters focus on the different cosmological models. In §5 dark energy is considered connected to the holographic principle and posits that it interacts (also non-gravitationally) with dark matter. The holographic principle sets a length scale, in this case the Hubble length, i.e., the scale of the causally connected events. In §6 the previous model is studied more deeply and an alternative to it is presented. Both models share identical background evolution but each component behaves differently, which induces a diverse behavior at the perturbative level. This allows to observationally discriminate one model from the other. A further holographic dark energy model is proposed in §7; this one based on the Ricci length (i.e., the maximum size a perturbation can have leading to a black hole). Again, a non-gravitational interaction is assumed between dark energy and dark matter. In §8, a unified dark model (featuring a unification between dark matter ad dark energy) previously proposed is studied. Since the parameter space that fits the observational data is very narrow (and also in view of its theoretical interest), we decompose the single energy component into cold dark matter and quantum vacuum interacting with one another. As a consequence the allowed parameter space gets substantially augmented. Although the models mentioned above mimic at the background level the standard ΛCDM model, the dark components evolve very differently. To rigorously study them, the numerical codes for the cosmological perturbations must be suitably modified, with the drawback of notably increasing the computational time. This is much alleviated in §9 where a novel method to calculate the matter power spectrum of dark energy models is proposed. Finally, in §10 three model independent parameterizations of the deceleration parameter, based on solid thermodynamic arguments, are proposed and contrasted with the observational data.
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Tamanini, N. « Dynamical systems in dark energy models ». Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1456304/.

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This PhD thesis is devoted to the study of dynamical systems appearing in theoretical models of dark energy. The quest for understanding the origin of the observed cosmic acceleration has led physicists to advance a large number of phenomenological explanations based on different fundamental theories. The best approach to analyse the background cosmological impli- cations of all these models consists in employing dynamical systems tech- niques. In this thesis, after reviewing elements of dynamical systems theory and basic cosmology, several dynamical systems, which arise in dark energy models ranging from scalar fields to modified gravity, will be studied using both analytical and numerical methods. The work is organised in order to present as many details as possible for the simpler and well known models, while outlining major results and referring to the literature for the less stud- ied ones. This choice aims at providing the reader with a complete overview and summary of dynamical systems in dark energy applications.
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Costa, André Alencar da. « Observational Constraints on Models with an Interaction between Dark Energy and Dark Matter ». Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-20012015-123002/.

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In this thesis we go beyond the standard cosmological LCDM model and study the effect of an interaction between dark matter and dark energy. Although the LCDM model provides good agreement with observations, it faces severe challenges from a theoretical point of view. In order to solve such problems, we first consider an alternative model where both dark matter and dark energy are described by fluids with a phenomenological interaction given by a combination of their energy densities. In addition to this model, we propose a more realistic one based on a Lagrangian density with a Yukawa-type interaction. To constrain the cosmological parameters we use recent cosmological data, the CMB measurements made by the Planck satellite, as well as BAO, SNIa, H0 and Lookback time measurements.
Nesta tese vamos além do modelo cosmológico padrão, o LCDM, e estudamos o efeito de uma interação entre a matéria e a energia escuras. Embora o modelo LCDM esteja de acordo com as observações, ele sofre sérios problemas teóricos. Com o objetivo de resolver tais problemas, nós primeiro consideramos um modelo alternativo, onde ambas, a matéria e a energia escuras, são descritas por fluidos com uma interação fenomenológica dada como uma combinação das densidades de energia. Além desse modelo, propomos um modelo mais realista baseado em uma densidade Lagrangiana com uma interação tipo Yukawa. Para vincular os parâmetros cosmológicos usamos dados cosmológicos recentes como as medidas da CMB feitas pelo satélite Planck, bem como medidas de BAO, SNIa, H0 e Lookback time.
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Zsembinszki, Gabriel. « Light scalar fields in a dark universe : models of inflation, dark energy and dark matter ». Doctoral thesis, Universitat Autònoma de Barcelona, 2007. http://hdl.handle.net/10803/3390.

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La teoría científica de más éxito hoy en día, sobre el origen y la evolución del universo, es conocida como el modelo estándar del Big Bang, el cual es una de las construcciones intelectuales más ambiciosas de la humanidad. Se basa en dos ramas bien consolidadas de la física teórica, a saber, la teoría de la Relatividad General y el Modelo Estándar de la física de partículas, y es capaz de hacer predicciones sólidas, como la expansión del universo, la existencia del fondo de radiación de microondas y las abundancias relativas de los elementos ligeros. Algunas de las predicciones teóricas ya han sido confirmadas por observaciones muy precisas.
Según la cosmología estándar del Big Bang, el universo primitivo consistía en un plasma muy caliente y denso que se expandió y se enfrió continuamente hasta el presente, dando paso a una serie de transiciones de fase cosmológicas, donde las teorías que describen el universo en cada fase son distintas. Dado que las energías del universo primitivo fueron mucho más altas que las alcanzadas en experimentos terrestres, el estudio del universo primitivo podría ofrecernos importantes informaciones sobre nuevas interacciones y nuevas partículas, abriendo nuevas direcciones para la extensión del Modelo Estándar de la física de partículas.
Como ya he mencionado anteriormente, durante la expansión del universo ocurrieron varias transiciones de fase que dejaron su huella sobre el estado presente del universo. Las observaciones sugieren que durante una de estas transiciones de fase, el universo primitivo sufrió un periodo de expansión acelerada, conocido como inflación. Aunque no forma parte de la cosmología estándar, la inflación es capaz de solucionar de una manera simple y elegante casi todos los problemas relacionados con el modelo estándar del Big Bang, y debería tenerse en cuenta en cualquier extensión posible de la teoría. Las observaciones también revelan la existencia de dos formas de energía desconocidas, a saber, materia oscura y energía oscura. La materia oscura es una forma de materia no relativista y no bariónica, que solamente puede ser detectada indirectamente, mediante su interacción con la materia normal. La energía oscura es un tipo de sustancia con presión negativa, que empezó a dominar recientemente y que es la causa de la aceleración de la expansión del universo.
En esta tesis doctoral presento varios modelos originales propuestos para resolver algunos de los problemas de la cosmología estándar, como posibles extensiones del modelo del Big Bang. Algunos de estos modelos introducen nuevas simetrías y partículas con el fin de explicar la inflación y la energía oscura y/o la materia oscura en una descripción unificada. Uno de los modelos es propuesto para explicar la energía oscura del universo, a través de un nuevo campo escalar que oscila en un potencial.
The most successful scientific theory today about the origin and evolution of the universe is known as the standard Big Bang model, which is one of the most ambitious intellectual constructions of the humanity. It is based on two consolidated branches of theoretical physics, namely, the theory of General Relativity and the Standard Model of particle physics, and is able to make robust predictions, such as the expansion of the universe, the existence of the cosmic microwave background radiation and the relative primordial abundance of light elements. Some of the theoretical predictions have already been confirmed by very precise observations.
According to the standard Big Bang cosmology, the early universe consisted of a very hot and dense plasma that continuously expanded and cooled up to the present, giving place to a series of cosmological phase transitions, where the theories describing the universe in each phase are different. Given that the energies of the early universe were much higher than those reached in terrestrial experiments, the study of the early universe might give us important information about new interactions and new particles, opening new directions for extending the Standard Model of particle physics.
As already mentioned above, during the expansion of the universe, different phase transitions occurred, which left their imprint on the present state of the universe. Observations suggest that during a very early phase transition the universe suffered a stage of accelerated expansion, known as inflation. Although inflation is not included in the standard cosmology, it is able to solve in a simple and elegant manner almost all of the shortcomings related to the standard Big Bang model, and should be taken into account in any possible extension of the theory. Observations also reveal evidence of the existence of two unknown forms of energy, i.e., dark matter and dark energy. Dark matter is a form of non-relativistic and non-baryonic matter, which can only be detected indirectly, by its gravitational interactions with normal matter. Dark energy is a kind of substance with negative pressure, which started to dominate recently and causes the accelerated expansion of the universe.
In this PhD Thesis, I present a few original models proposed to solve some of the shortcomings of the standard cosmology, as possible extensions of the Big Bang model. Some of these models introduce new symmetries and particles in order to explain inflation and dark energy and/or dark matter in a unified description. One of the models is proposed for explaining the dark energy of the universe, by means of a new scalar field oscillating in a potential.
The most successful scientific theory today about the origin and evolution of the universe is known as the standard Big Bang model, which is one of the most ambitious intellectual constructions of the humanity. It is based on two consolidated branches of theoretical physics, namely, the theory of General Relativity and the Standard Model of particle physics, and is able to make robust predictions, such as the expansion of the universe, the existence of the cosmic microwave background radiation and the relative primordial abundance of light elements. Some of the theoretical predictions have already been confirmed by very precise observations.
According to the standard Big Bang cosmology, the early universe consisted of a very hot and dense plasma that continuously expanded and cooled up to the present, giving place to a series of cosmological phase transitions, where the theories describing the universe in each phase are different. Given that the energies of the early universe were much higher than those reached in terrestrial experiments, the study of the early universe might give us important information about new interactions and new particles, opening new directions for extending the Standard Model of particle physics.
As already mentioned above, during the expansion of the universe, different phase transitions occurred, which left their imprint on the present state of the universe. Observations suggest that during a very early phase transition the universe suffered a stage of accelerated expansion, known as inflation. Although inflation is not included in the standard cosmology, it is able to solve in a simple and elegant manner almost all of the shortcomings related to the standard Big Bang model, and should be taken into account in any possible extension of the theory. Observations also reveal evidence of the existence of two unknown forms of energy, i.e., dark matter and dark energy. Dark matter is a form of non-relativistic and non-baryonic matter, which can only be detected indirectly, by its gravitational interactions with normal matter. Dark energy is a kind of substance with negative pressure, which started to dominate recently and causes the accelerated expansion of the universe.
In this PhD Thesis, I present a few original models proposed to solve some of the shortcomings of the standard cosmology, as possible extensions of the Big Bang model. Some of these models introduce new symmetries and particles in order to explain inflation and dark energy and/or dark matter in a unified description. One of the models is proposed for explaining the dark energy of the universe, by means of a new scalar field oscillating in a potential.
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Mania, Data. « Constraints on dark energy models from observational data ». Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/14178.

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Master of Science
Department of Physics
Bharat Ratra
Recent observations in cosmology suggest that the universe is undergoing accelerating expansion. Mysterious component responsible for acceleration is called "Dark Energy" contributing to 70% of total energy density of the universe. Simplest DE model is [Lambda]CDM, where Einstein’s cosmological constant plays role of the dark energy. Despite the fact that it is consistent with observational data, it leaves some important theoretical questions unanswered. To overcome these difficulties different Dark energy models are proposed. Two of these models XCDM parametrization and slow rolling scalar field model [phi]CDM, along with "standard" [Lambda]CDM are disscussed here, constraining their parameter set. In this thesis we start with a general theoretical overview of basic ideas and distance measures in cosmology. In the following chapters we use H II starburst galaxy apparent magnitude versus redshift data from Siegel et al.(2005) to constrain DE model parameters. These constraints are generally consistent with those derived using other data sets, but are not as restrictive as the tightest currently available constraints. Also we constrain above mentioned cosmological models in light of 32 age measurements of passively evolving galaxies as a function of redshift and recent estimates of the product of the cosmic microwave background acoustic scale and the baryon acoustic oscillation peak scale.
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Rivera, Echeverri José David [UNESP]. « ISW effect through dark energy quintessence and ΛCDM models ». Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/92030.

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Made available in DSpace on 2014-06-11T19:25:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-21Bitstream added on 2014-06-13T20:26:58Z : No. of bitstreams: 1 riveraecheverri_jd_me_ift.pdf: 457386 bytes, checksum: 5d639a5ed022bc76e4f1ab784a47e8e7 (MD5)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Observações atuais do satélite Wilkinson Microwave Anisotropy Probe (WMAP) da Radiação Cósmica de Fundo (CMB) e estruturas de grande escala (LSS) têm permitido melhorar os estudos das anisotropias secundárias, especialmente o efeito Sachs-Wolfe Integrado (ISW). Usando a correlação cruzada entre a CMB e mapas da LSS, o sinal do efeito ISW pode ser detectado. Nós podemos usar o efeito ISW junto com o modelo cosmológico padrão (neste caso o Universo esta dominado pela constante cosmológica e a Matéria Escura Fria, ΛCDM) mais algoritmos numéricos para restringir os parâmetros em um modelo cosmológico com energia escura. Para diferentes casos com um único parâmetro livre de um model de Quintessência parametrizado,' w IND. 0' < 0 e 2,0 < 'w IND. a' <−2,0, podemos encontrar bins de largura [−1,926,−0,323] em 'w ind. 0' e [−0,855, 1,190]. Nestes intervalos, obtemos um sigma de nivel tomando o 68% da amostra que melhor se ajusta ao modelo cosmológico padrão
Current observations of the Wilkinson Microwave Anisotropy Probe (WMAP) satellite of Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) have allowed to improve studies of the secondary anisotropies, especially the Integrated Sachs-Wolfe effect (ISW). Using the cross-correlation between the CMB and LSS maps, the ISW effect signal can be detected. We can use the ISW effect together with standard cosmological model (in this case the Universe is dominated by the cosmological constant and Cold Dark Matter, ΛCDM) plus numerical algorithms to constrain the parameters in a cosmological model with dark energy. For cases different with a single free parameter of a parameterised Quintessence model, 'w ind. 0' < 0 and 2,0 < 'w ind. a' <−2,0, we can find bins of width [−1,926,−0,323] in 'w ind. 0' and [−0,855, 1,190] in wa. In these intervals, we obtain one sigma level by taking the 68% of the sample which best fit the standard cosmological model
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Rivera, Echeverri José David. « ISW effect through dark energy quintessence and ΛCDM models / ». São Paulo, 2013. http://hdl.handle.net/11449/92030.

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Orientador: Maria Cristina Batoni Abdalla Ribeiro
Coorientador: Felipe Batoni Abdalla
Banca: Marcos Vinícius Borges Teixeira Lima
Banca: Laerte Sodré Junior
Resumo: Observações atuais do satélite Wilkinson Microwave Anisotropy Probe (WMAP) da Radiação Cósmica de Fundo (CMB) e estruturas de grande escala (LSS) têm permitido melhorar os estudos das anisotropias secundárias, especialmente o efeito Sachs-Wolfe Integrado (ISW). Usando a correlação cruzada entre a CMB e mapas da LSS, o sinal do efeito ISW pode ser detectado. Nós podemos usar o efeito ISW junto com o modelo cosmológico padrão (neste caso o Universo esta dominado pela constante cosmológica e a Matéria Escura Fria, ΛCDM) mais algoritmos numéricos para restringir os parâmetros em um modelo cosmológico com energia escura. Para diferentes casos com um único parâmetro livre de um model de Quintessência parametrizado,' w IND. 0' < 0 e 2,0 < 'w IND. a' <−2,0, podemos encontrar bins de largura [−1,926,−0,323] em 'w ind. 0' e [−0,855, 1,190]. Nestes intervalos, obtemos um sigma de nivel tomando o 68% da amostra que melhor se ajusta ao modelo cosmológico padrão
Abstract: Current observations of the Wilkinson Microwave Anisotropy Probe (WMAP) satellite of Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) have allowed to improve studies of the secondary anisotropies, especially the Integrated Sachs-Wolfe effect (ISW). Using the cross-correlation between the CMB and LSS maps, the ISW effect signal can be detected. We can use the ISW effect together with standard cosmological model (in this case the Universe is dominated by the cosmological constant and Cold Dark Matter, ΛCDM) plus numerical algorithms to constrain the parameters in a cosmological model with dark energy. For cases different with a single free parameter of a parameterised Quintessence model, 'w ind. 0' < 0 and 2,0 < 'w ind. a' <−2,0, we can find bins of width [−1,926,−0,323] in 'w ind. 0' and [−0,855, 1,190] in wa. In these intervals, we obtain one sigma level by taking the 68% of the sample which best fit the standard cosmological model
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Pavlov, Anatoly. « Constraining competing models of dark energy with cosmological observations ». Diss., Kansas State University, 2015. http://hdl.handle.net/2097/20345.

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Doctor of Philosophy
Department of Physics
Bharat Ratra
The last decade of the 20th century was marked by the discovery of the accelerated expansion of the universe. This discovery puzzles physicists and has yet to be fully understood. It contradicts the conventional theory of gravity, i.e. Einstein’s General Relativity (GR). According to GR, a universe filled with dark matter and ordinary matter, i.e. baryons, leptons, and photons, can only expand with deceleration. Two approaches have been developed to study this phenomenon. One attempt is to assume that GR might not be the correct description of gravity, hence a modified theory of gravity has to be developed to account for the observed acceleration of the universe’s expansion. This approach is known as the ”Modified Gravity Theory”. The other way is to assume that the energy budget of the universe has one more component which causes expansion of space with acceleration on large scales. Dark Energy (DE) was introduced as a hypothetical type of energy homogeneously filling the entire universe and very weakly or not at all interacting with ordinary and dark matter. Observational data suggest that if DE is assumed then its contribution to the energy budget of the universe at the current epoch should be about 70% of the total energy density of the universe. In the standard cosmological model a DE term is introduced into the Einstein GR equations through the cosmological constant, a constant in time and space, and proportional to the metric tensor g[subscript]mu[subscript]nu. While this model so far fits most available observational data, it has some significant conceptual shortcomings. Hence there are a number of alternative cosmological models of DE in which the dark energy density is allowed to vary in time and space.
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Weller, Joel Martin. « Models of onflation and dark energy with coupled scalar fields ». Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538088.

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Livres sur le sujet "Dark energy models"

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Prime elements of ordinary matter, dark matter & dark energy : Beyond standard model & string theory. 2e éd. Boca Raton, FL : Universal Publishers, 2007.

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From quantum to cosmos : Fundamental physics research in space. Hackensack, N.J : World Scientific, 2009.

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E'kov, Evgeniy. The origin and evolution of the Universe. ru : INFRA-M Academic Publishing LLC., 2022. http://dx.doi.org/10.12737/1852616.

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The monograph examines a wide range of problems related to the origin and development of the Universe. An overview of the history of the study of astronomy from Stone Age observatories to modern space telescopes is given. The theories of the origin of the Universe are analyzed, evidence of the Big Bang, the expansion of the Universe, the cosmic effects of dark energy and dark matter are given. The origin and causes of the existence of planets, stars, nebulae, galaxies and other cosmic bodies in the Universe are considered. A large place is given to the analysis of the origin and development of the Solar system. The origin and functioning of the Sun, planets and other objects located in its gravitational field are considered. Among the planets of the Solar System, the greatest attention is paid to the Earth and the analysis of the factors that ensured the emergence and maintenance of various forms of life on it. For a wide range of readers interested in the origin and evolution of the universe. It can be useful for students, postgraduates and teachers of physics and mathematics universities.
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Blaha, Stephen. The origin of the standard model : The genesis of four quark and lepton species, parity violation, the electro weak sector, color SU(3), three visible generations of fermions, and one generation of dark matter with dark energy ; Quantum theory of the third kind : a new type of divergence-free quantum field theory supporting a unified standard model of elementary particles and quantum gravity based on a new method in the calculus of variations. Auburn, NH : Pingree-Hill Publishing, 2006.

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Stern, Steffen. Dynamical dark energy and variation of fundamental'constants' : A study of experimental probes and theoretical models. Südwestdeutscher Verlag für Hochschulschriften AG & Company KG, 2009.

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Saha, Prasenjit, et Paul A. Taylor. The Expanding Universe. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198816461.003.0008.

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This chapter covers the now generally accepted ‘concordance model’ of the Universe, along with a few other historical models that were leading candidates previously. The theoretical underpinnings of the Cosmological Principle and its observational evidence are presented. The formalism of the Friedmann equation and the Robertson–Walker metric are introduced (without derivation), and the key concepts of lookback time and comoving distance are explained. The different mass–energy constituents in the concordance cosmology (including curvature, dark matter, and dark energy) are also described, along with their developmental histories. As a somewhat tangential but exciting development, the production of gravitational waves from compact object binaries is explained using semi-classical arguments.
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Ginzburg, Vladimir. Prime Elements Of Ordinary Matter, Dark Matter & Dark Energy - Beyond Standard Model & String Theory. Lulu.com, 2007.

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Ginzburg, Vladimir B. Prime Elements of Ordinary Matter, Dark Matter & Dark Energy : Beyond Standard Model & String Theory. Universal Publishers, 2007.

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Tatum, Eugene Terry, et U. V. S. Seshavatharam. Flat Space Cosmology : A New Model of the Universe Incorporating Astronomical Observations of Black Holes, Dark Energy and Dark Matter. Universal Publishers, 2021.

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Lander, Enrique. Integral Theory of the Universe : New Model of the Universe, Without Energy or Dark Matter. Independently Published, 2020.

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Chapitres de livres sur le sujet "Dark energy models"

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Tsujikawa, S. « Modified Gravity Models of Dark Energy ». Dans Lectures on Cosmology, 99–145. Berlin, Heidelberg : Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-10598-2_3.

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Dimopoulos, Konstantinos. « Models of Inflation ». Dans Introduction to Cosmic Inflation and Dark Energy, 137–70. First edition. | Boca Raton : CRC Press, 2020. | Series : Series in astronomy and astrophysics : CRC Press, 2020. http://dx.doi.org/10.1201/9781351174862-7.

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Tsujikawa, Shinji. « Dark Energy : Observational Status and Theoretical Models ». Dans Quantum Gravity and Quantum Cosmology, 289–331. Berlin, Heidelberg : Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-33036-0_11.

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Macció, A. V., S. A. Bonometto, R. Mainini et A. Klypin. « Structure Formation in Dynamical Dark Energy Models ». Dans Multiwavelength Cosmology, 199–202. Dordrecht : Springer Netherlands, 2004. http://dx.doi.org/10.1007/0-306-48570-2_41.

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Guendelman, Eduardo, Emil Nissimov et Svetlana Pacheva. « Wheeler–DeWitt Quantization of Gravity Models of Unified Dark Energy and Dark Matter ». Dans Quantum Theory and Symmetries with Lie Theory and Its Applications in Physics Volume 2, 99–113. Singapore : Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-2179-5_7.

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Zakharov, A. F., S. Capozziello, F. De Paolis, G. Ingrosso et A. A. Nucita. « The Role of Dark Matter and Dark Energy in Cosmological Models : Theoretical Overview ». Dans Probing The Nature of Gravity, 353–65. New York, NY : Springer New York, 2009. http://dx.doi.org/10.1007/978-1-4419-1362-3_22.

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Arnowitt, R., B. Dutta et Y. Santoso. « Neutralino Proton Cross Sections for Dark Matter in SUGRA and D-BRANE Models ». Dans Sources and Detection of Dark Matter and Dark Energy in the Universe, 222–35. Berlin, Heidelberg : Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/978-3-662-04587-9_23.

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Staicova, Denitsa, et Michail Stoilov. « Cosmological Solutions from Models with Unified Dark Energy and Dark Matter and with Inflaton Field ». Dans Quantum Theory and Symmetries with Lie Theory and Its Applications in Physics Volume 2, 251–60. Singapore : Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-2179-5_19.

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Chattopadhyay, Surajit, et Antonio Pasqua. « Consequences of Holographic Scalar Field Dark Energy Models in Chameleon Brans-Dicke Cosmology ». Dans Springer Proceedings in Physics, 487–92. Cham : Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-25619-1_74.

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Cunillera, Francesc. « Obstructions to Quintessence Model Building ». Dans Dark Energy, 131–70. Cham : Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-21468-4_8.

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Actes de conférences sur le sujet "Dark energy models"

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Caldwell, Robert R. « Dark Energy Models ». Dans Proceedings of the 2012 Theoretical Advanced Study Institute in Elementary Particle Physics. WORLD SCIENTIFIC, 2013. http://dx.doi.org/10.1142/9789814525220_0001.

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Besprosvany, Jaime, Germán Izquierdo, Alfredo Macias et Marco Maceda. « Dark-energy thermodynamic models ». Dans RECENT DEVELOPMENTS IN GRAVITATION AND BEC’S PHENOMENOLOGY : IV Mexican Meeting on Experimental and Theoretical Physics : Symposium on Gravitation BEC’s Phenomenology. AIP, 2010. http://dx.doi.org/10.1063/1.3531619.

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Copeland, Edmund J., Jean-Michel Alimi et André Fuözfa. « Models of Dark Energy ». Dans INVISIBLE UNIVERSE : Proceedings of the Conference. AIP, 2010. http://dx.doi.org/10.1063/1.3462965.

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GANNOUJI, R., D. POLARSKI, A. RANQUET et A. A. STAROBINSKY. « SCALAR-TENSOR DARK ENERGY MODELS ». Dans Proceedings of the MG11 Meeting on General Relativity. World Scientific Publishing Company, 2008. http://dx.doi.org/10.1142/9789812834300_0259.

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Zimdahl, W. « Models of interacting dark energy ». Dans I COSMOSUL : COSMOLOGY AND GRAVITATION IN THE SOUTHERN CONE. AIP, 2012. http://dx.doi.org/10.1063/1.4756811.

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Chan, R., M. A. F. da Silva, Jaime F. Villas da Rocha, Jean-Michel Alimi et André Fuözfa. « Star Models with Dark Energy ». Dans INVISIBLE UNIVERSE : Proceedings of the Conference. AIP, 2010. http://dx.doi.org/10.1063/1.3462618.

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Gao, Changjun, Yan Gong, Xuelei Chen, Carlo Luciano Bianco et She-Sheng Xue. « Phenomenological Models of dark Energy ». Dans RELATIVISTIC ASTROPHYSICS : 4th Italian-Sino Workshop. AIP, 2008. http://dx.doi.org/10.1063/1.2836987.

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Lazkoz, Ruth, Mauricio Carbajal, Luis Manuel Montaño, Oscar Rosas-Ortiz, Sergio A. Tomas Velazquez et Omar Miranda. « Geometrical Constraints on Dark Energy Models ». Dans Advanced Summer School in Physics 2007. AIP, 2007. http://dx.doi.org/10.1063/1.2825127.

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Chimento, Luis P. « Exactly solved models of interacting dark matter and dark energy ». Dans I COSMOSUL : COSMOLOGY AND GRAVITATION IN THE SOUTHERN CONE. AIP, 2012. http://dx.doi.org/10.1063/1.4756808.

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Kumar, Jason. « WIMPless Dark Matter : Models and Signatures ». Dans 35th International Conference of High Energy Physics. Trieste, Italy : Sissa Medialab, 2011. http://dx.doi.org/10.22323/1.120.0438.

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Rapports d'organisations sur le sujet "Dark energy models"

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Abdallah, Jalal, Adi Ashkenazi, Antonio Boveia, Giorgio Busoni, Andrea De Simone, Caterina Doglioni, Aielet Efrati et al. Simplified Models for Dark Matter and Missing Energy Searches at the LHC. Office of Scientific and Technical Information (OSTI), octobre 2014. http://dx.doi.org/10.2172/1304777.

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Boveia, Antonio, Oliver Buchmueller, Giorgio Busoni, Francesco D' Eramo, Albert De Roeck, Andrea De Simone, Caterina Doglioni et al. Recommendations on presenting LHC searches for missing transverse energy signals using simplified s-channel models of dark matter. Office of Scientific and Technical Information (OSTI), mars 2016. http://dx.doi.org/10.2172/1255141.

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Farbin, Amir. DoE Early Career Research Program : Final Report : Model-Independent Dark-Matter Searches at the ATLAS Experiment and Applications of Many-core Computing to High Energy Physics. Office of Scientific and Technical Information (OSTI), juillet 2015. http://dx.doi.org/10.2172/1193786.

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Vieitez Martínez, Daniel. Introducción a las mejores prácticas de los modelos internacionales de asociaciones público-privadas. Inter-American Development Bank, janvier 2010. http://dx.doi.org/10.18235/0007604.

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Presentación expuesta durante el Tercer Encuentro de Capacitación en Materia de Estructuración de Proyectos de Asociación Público Privada, llevado a cabo en Mérida, Yucatán, México, el 20, 21 y 22 de enero de 2010. La Coordinación Técnica del Programa para el Impulso de Asociaciones Público-Privadas en Estados Mexicanos (PIAPPEM) está coordinando, supervisando y elaborando unos Documentos de Apoyo para el desarrollo de infraestructura y la provisión de servicios públicos bajo esquemas de Alianzas Público Privadas (APP). El objetivo es dar a conocer las mejores prácticas contractuales, técnicas, financieras y metodológicas de esquemas APP para que puedan ser aprovechadas por los estados participantes del PIAPPEM. Esta presentación tiene como objetivo dar a conocer un contexto general de las APPs en México, incluyendo los documentos legales, los aspectos técnicos y la guía metodológica para desarrollar un taller de análisis de riesgos. Asimismo, se describen las experiencias internacionales en APPs y la forma en que esta práctica ha tenido auge en diferentes regiones del mundo.
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