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Journal articles on the topic 'Big Bang Nucleosynthesis (BBN)'

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Published: 6 September 2023

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1

Schramm, D. N. "Big Bang Nucleosynthesis." Symposium - International Astronomical Union 187 (2002): 1–15. http://dx.doi.org/10.1017/s0074180900113695.

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Big Bang Nucleosynthesis (BBN) is on the verge of undergoing a transformation now that extragalactic deuterium is being measured. Previously, the emphasis was on demonstrating the concordance of the Big Bang Nucleosynthesis model with the abundances of the light isotopes extrapolated back to their primordial values using stellar and Galactic evolution theories. Once the primordial deuterium abundance is converged upon, the nature of the field will shift to using the much more precise primordial D/H to constrain the more flexible stellar and Galactic evolution models (although the question of p
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2

Steigman, Gary. "Neutrinos and Big Bang Nucleosynthesis." Advances in High Energy Physics 2012 (2012): 1–24. http://dx.doi.org/10.1155/2012/268321.

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According to the standard models of particle physics and cosmology, there should be a background of cosmic neutrinos in the present Universe, similar to the cosmic microwave photon background. The weakness of the weak interactions renders this neutrino background undetectable with current technology. The cosmic neutrino background can, however, be probed indirectly through its cosmological effects on big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) radiation. In this BBN review, focused on neutrinos and more generally on dark radiation, the BBN constraints on the number
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Foley, M., N. Sasankan, M. Kusakabe, and G. J. Mathews. "Revised uncertainties in Big Bang Nucleosynthesis." International Journal of Modern Physics E 26, no. 08 (2017): 1741008. http://dx.doi.org/10.1142/s0218301317410087.

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Big Bang Nucleosynthesis (BBN) explores the first few minutes of nuclei formation during the Big Bang. We present updated 2[Formula: see text] for the abundances of the four primary light nuclides — D, 3He, 4He, and 7Li — in BBN. A modified standard BBN code was used in a Monte Carlo analysis of the nucleosynthesis uncertainties as a function of the baryon-to-photon ratio. Reaction rates were updated to those of NACRE, REACLIB, and [Formula: see text]-Matrix calculations. The results were then used to derive a new constraint on the effective number of neutrinos.
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Pospelov, M. "Catalyzed Big-Bang nucleosynthesis." Canadian Journal of Physics 86, no. 4 (2008): 611–16. http://dx.doi.org/10.1139/p07-206.

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We point out that the existence of metastable, τ >103 s, negatively charged electroweak-scale particles (X–) alters the predictions for lithium and other primordial elemental abundances for A > 4 via the formation of bound states with nuclei during Big-Bang nucleosynthesis (BBN). In particular, we show that the bound states of X– with helium, formed at temperatures of about T = 108 K, lead to the catalytic enhancement of 6Li production, which is eight orders of magnitude more efficient than the standard channel. In particle physics models, where subsequent decay of X– does not lead to la
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5

Coc, Alain, and Elisabeth Vangioni. "Primordial nucleosynthesis." International Journal of Modern Physics E 26, no. 08 (2017): 1741002. http://dx.doi.org/10.1142/s0218301317410026.

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Primordial nucleosynthesis, or big bang nucleosynthesis (BBN), is one of the three evidences for the big bang model, together with the expansion of the universe and the cosmic microwave background. There is a good global agreement over a range of nine orders of magnitude between abundances of 4He, D, 3He and 7Li deduced from observations, and calculated in primordial nucleosynthesis. However, there remains a yet-unexplained discrepancy of a factor [Formula: see text], between the calculated and observed lithium primordial abundances, that has not been reduced, neither by recent nuclear physics
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Yeh, Tsung-Han, Keith A. Olive, and Brian D. Fields. "The Neutron Mean Life and Big Bang Nucleosynthesis." Universe 9, no. 4 (2023): 183. http://dx.doi.org/10.3390/universe9040183.

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We explore the effect of neutron lifetime and its uncertainty on standard big bang nucleosynthesis (BBN). BBN describes the cosmic production of the light nuclides, 1H, D, 3H+3He, 4He, and 7Li+7Be, in the first minutes of cosmic time. The neutron mean life τn has two roles in modern BBN calculations: (1) it normalizes the matrix element for weak n↔p interconversions, and (2) it sets the rate of free neutron decay after the weak interactions freeze-out. We review the history of the interplay between τn measurements and BBN, and present a study of the sensitivity of the light element abundances
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Hwang, Eunseok, Dukjae Jang, Kiwan Park, et al. "Dynamical screening effects on big bang nucleosynthesis." Journal of Cosmology and Astroparticle Physics 2021, no. 11 (2021): 017. http://dx.doi.org/10.1088/1475-7516/2021/11/017.

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Abstract A moving ion in plasma creates a deformed electric potential depending on the ion velocity, which leads to the distinct screening effect compared to the standard static Salpeter formula. In this paper, adopting the test charge method, we explore the dynamical screening effects on big bang nucleosynthesis (BBN). We find that the high temperature in the early universe causes the ion velocity to be faster than the solar condition so that the electric potential is effectively polarized. However, the low density of background plasma components significantly suppresses the dynamical screeni
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8

VILLANTE, F. L. "BBN AND NEUTRINO OSCILLATIONS IN THE EARLY UNIVERSE: A BRIEF REVIEW." International Journal of Modern Physics A 20, no. 11 (2005): 2431–35. http://dx.doi.org/10.1142/s0217751x05024729.

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9

KAMIMURA, M., Y. KINO, and E. HIYAMA. "STAU-CATALYZED BIG-BANG NUCLEOSYNTHESIS AND NUCLEAR CLUSTER MODEL." International Journal of Modern Physics A 24, no. 11 (2009): 2076–83. http://dx.doi.org/10.1142/s0217751x09045649.

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Three-body cluster-model calculations are performed for the new types of big-bang nucleosynthesis (BBN) reactions that are calalyzed by a supersymmetric (SUSY) particle stau, a scalar partner of the tau lepton. If a stau has a lifetime ≳ 103s, it would capture a light element previously synthesized in standard BBN and form a Coulombic bound state. The bound state, an exotic atom, is expected to induce various reactions, such as (αX-) + d → 6 Li + X-, in which a negatively charged stau (denoted as X-) works as a catalyzer. Recent literature papers have claimed that some of these stau-catalyzed
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10

Makki, Tahani, and Mounib El Eid. "Big Bang Nucleosynthesis (BBN) and Non-Standard Physics." EPJ Web of Conferences 184 (2018): 02009. http://dx.doi.org/10.1051/epjconf/201818402009.

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A brief overview on standard big bang nucleosynthesis (shortly, SBBN) is presented. First, we describe the outcome of the SBBN concerning the abundances of the light elements up to 7Li. A comparison with observations reveals a Lithium overproduction, which is not understood yet and is termed as “Cosmological Lithium Problem”. Resolving that problem is not easy, since many aspects are involved whichnuclear, astrophysical and even a non-standard scenario may be invoked. These items are described in some details owing to the limited available space.
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11

Asimakis, Petros, Emmanuel N. Saridakis, Spyros Basilakos, and Kuralay Yesmakhanova. "Big Bang Nucleosynthesis Constraints on f(T,TG) Gravity." Universe 8, no. 9 (2022): 486. http://dx.doi.org/10.3390/universe8090486.

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We confront f(T,TG) gravity, with big bang nucleosynthesis (BBN) requirements. The former is obtained using both the torsion scalar, as well as the teleparallel equivalent of the Gauss–Bonnet term, in the Lagrangian, resulting to modified Friedmann equations in which the extra torsional terms constitute an effective dark energy sector. We calculate the deviations of the freeze-out temperature Tf, caused by the extra torsion terms in comparison to ΛCDM paradigm. Then, we impose five specific f(T,TG) models and extract the constraints on the model parameters in order for the ratio |ΔTf/Tf| to sa
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12

Kusakabe, Motohiko, Toshitaka Kajino, Takashi Yoshida, and Grant J. Mathews. "Big Bang nucleosynthesis with long-lived strongly interacting relic particles." Proceedings of the International Astronomical Union 5, S268 (2009): 33–38. http://dx.doi.org/10.1017/s1743921310003832.

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AbstractWe study effects of relic long-lived strongly interacting massive particles (X particles) on big bang nucleosynthesis (BBN). The X particle is assumed to have existed during the BBN epoch, but decayed long before detected. The interaction strength between an X and a nucleon is assumed to be similar to that between nucleons. Rates of nuclear reactions and beta decay of X-nuclei are calculated, and the BBN in the presence of neutral charged X0 particles is calculated taking account of captures of X0 by nuclei. As a result, the X0 particles form bound states with normal nuclei during a re
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13

Kohri, K., M. Kawasaki, and Katsuhiko Sato. "Big Bang Nucleosynthesis and Lepton Number Asymmetry in the Universe." Symposium - International Astronomical Union 183 (1999): 312. http://dx.doi.org/10.1017/s0074180900133030.

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Recently it has been reported that there may be a discrepancy between big bang nucleosynthesis theory and observations (BBN crisis) (Hata et al., 1995). One way to solve the discrepancy might be to adopt some modifications of standard physics used in SBBN (Kawasaki et al, 1997). We show that BBN predictions agree with the primordial abundances of light elements, 4He, D, 3He and 7Li inferred from the observational data if the electron neutrino has a net chemical potential ξve due to lepton asymmetry (Kohri et al., 1997). We study BBN with the effects of the neutrino degeneracy in details using
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14

Jang, Dukjae, Youngshin Kwon, Kyujin Kwak, and Myung-Ki Cheoun. "Big Bang nucleosynthesis in a weakly non-ideal plasma." Astronomy & Astrophysics 650 (June 2021): A121. http://dx.doi.org/10.1051/0004-6361/202038478.

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We propose a correction of the standard Big Bang nucleosynthesis (BBN) scenario to resolve the primordial lithium problem by considering a possibility that the primordial plasma can deviate from the ideal state. In the standard BBN, the primordial plasma is assumed to be ideal, with particles and photons satisfying the Maxwell-Boltzmann and Planck distribution, respectively. We suggest that this assumption of the primordial plasma being ideal might oversimplify the early Universe and cause the lithium problem. We find that a deviation of photon distribution from the Planck distribution, which
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15

KUSAKABE, MOTOHIKO, TOSHITAKA KAJINO, RICHARD N. BOYD, TAKASHI YOSHIDA, and GRANT J. MATHEWS. "EFFECT OF NEGATIVELY-CHARGED MASSIVE PARTICLES ON BIG-BANG NUCLEOSYNTHESIS AND A SOLUTION TO THE LITHIUM PROBLEMS." Modern Physics Letters A 23, no. 17n20 (2008): 1668–74. http://dx.doi.org/10.1142/s0217732308028077.

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Spectroscopic observations of metal poor halo stars give an indication of a possible primordial plateau of 6 Li abundance as a function of metallicity similar to that for 7 Li . The inferred abundance of 6 Li is ~1000 times larger than that predicted by standard big bang nucleosynthesis (BBN) for the baryon-to-photon ratio inferred from the WMAP data, and that of 7 Li is about 3 times smaller than the prediction. We study a possible solution to both the problems of underproduction of 6 Li and overproduction of 7 Li in BBN. This solution involves a hypothetical massive, negatively-charged parti
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Pitrou, Cyril, Alain Coc, Jean-Philippe Uzan, and Elisabeth Vangioni. "A new tension in the cosmological model from primordial deuterium?" Monthly Notices of the Royal Astronomical Society 502, no. 2 (2021): 2474–81. http://dx.doi.org/10.1093/mnras/stab135.

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ABSTRACT Recent measurements of the D(p,γ)3He nuclear reaction cross-section and of the neutron lifetime, along with the reevaluation of the cosmological baryon abundance from cosmic microwave background (CMB) analysis, call for an update of abundance predictions for light elements produced during the big-bang nucleosynthesis (BBN). While considered as a pillar of the hot big-bang model in its early days, BBN constraining power mostly rests on deuterium abundance. We point out a new ≃1.8σ tension on the baryonic density, or equivalently on the D/H abundance, between the value inferred on one h
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Park, Tae-Sun, Kyung Joo Min, and Seung-Woo Hong. "Effects of transient nonthermal particles on the big bang nucleosynthesis." International Journal of Modern Physics E 29, no. 03 (2020): 2050012. http://dx.doi.org/10.1142/s0218301320500123.

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The effects of introducing a small amount of nonthermal distribution (NTD) of elements in big bang nucleosynthesis (BBN) are studied by allowing a fraction of the NTD to be time-dependent so that it contributes only during a certain period of the BBN evolution. The fraction is modeled as a Gaussian-shaped function of [Formula: see text], where [Formula: see text] is the temperature of the cosmos, and thus the function is specified by three parameters; the central temporal position, the width and the magnitude. The change in the average nuclear reaction rates due to the presence of the NTD is a
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STEIGMAN, GARY. "PRIMORDIAL NUCLEOSYNTHESIS: SUCCESSES AND CHALLENGES." International Journal of Modern Physics E 15, no. 01 (2006): 1–35. http://dx.doi.org/10.1142/s0218301306004028.

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Primordial nucleosynthesis provides a probe of the Universe during its early evolution. Given the progress exploring the constituents, structure, and recent evolution of the Universe, it is timely to review the status of Big Bang Nucleosynthesis (BBN) and to confront its predictions, and the constraints which emerge from them, with those derived from independent observations of the Universe at much later epochs in its evolution. Following an overview of the key physics controlling element synthesis in the early Universe, the predictions of the standard models of cosmology and particle physics
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19

Bertulani, Carlos A., Francis W. Hall, and Benjamin I. Santoyo. "Big Bang nucleosynthesis as a probe of new physics." EPJ Web of Conferences 275 (2023): 01003. http://dx.doi.org/10.1051/epjconf/202327501003.

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The Big Bang Nucleosynthesis (BBN) model is a cornerstone for the understanding of the evolution of the early universe, making seminal predictions that are in outstanding agreement with the present observation of light element abundances in the universe. Perhaps, the only remaining issue to be solved by theory is the so-called “lithium abundance problem". Dedicated experimental efforts to measure the relevant nuclear cross sections used as input of the model have lead to an increased level of accuracy in the prediction of the light element primordial abundances. The rise of indirect experiment
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Olive, Keith A. "The effects of coupling variations on BBN." Proceedings of the International Astronomical Union 5, H15 (2009): 305. http://dx.doi.org/10.1017/s1743921310009452.

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AbstractThe effect of variations of the fundamental nuclear parameters on big-bang nucleosynthesis are modeled and discussed in detail taking into account the interrelations between the fundamental parameters arising in unified theories. Considering only 4He, strong constraints on the variation of the neutron lifetime, neutron-proton mass difference are set. We show that a variation of the deuterium binding energy is able to reconcile the 7Li abundance deduced from the WMAP analysis with its spectroscopically determined value while maintaining concordance with D and 4He.
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Kusakabe, Motohiko, Grant J. Mathews, Toshitaka Kajino, and Myung-Ki Cheoun. "Review on effects of long-lived negatively charged massive particles on Big Bang Nucleosynthesis." International Journal of Modern Physics E 26, no. 08 (2017): 1741004. http://dx.doi.org/10.1142/s021830131741004x.

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We review important reactions in the Big Bang Nucleosynthesis (BBN) model involving a long-lived negatively charged massive particle, [Formula: see text], which is much heavier than nucleons. This model can explain the observed 7Li abundances of metal-poor stars, and predicts a primordial 9Be abundance that is larger than the standard BBN prediction. In the BBN epoch, nuclei recombine with the [Formula: see text] particle. Because of the heavy [Formula: see text] mass, the atomic size of bound states [Formula: see text] is as small as the nuclear size. The nonresonant recombination rates are t
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22

Luo, Yudong, Toshitaka Kajino, Motohiko Kusakabe, and Michael A Famiano. "Primordial Nucleosynthesis with a background magnetic field." EPJ Web of Conferences 227 (2020): 02003. http://dx.doi.org/10.1051/epjconf/202022702003.

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We present our recent detailed calculation of the impacts from a background magnetic field on Big Bang Nucleosynthesis (BBN). Namely, the magnetic field impacts on the electron-positron thermodynamics, time temper-ature relation and the screening potential of the early Universe. Most interest-ingly, we investigated the electron-positron relativistic screening potential with the background magnetic field, such potential might lead to a non trivial effect on the electron capture reaction which could finally affect the neutron to proton ratio.
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Sabeeh, Syeda, Muhammad Jawad, Abdul Kabir та Jameel-Un Nabi. "Re-examination of radiative capture of deuteron 3He(d,γ)5Li at low energy". Europhysics Letters 141, № 5 (2023): 54003. http://dx.doi.org/10.1209/0295-5075/acbf6f.

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Abstract 3He(d,γ)5Li is important in the Big Bang Nucleosynthesis (BBN), as it provides seeds for the 6Li formation. Within the framework of the potential model the 3He(d,γ)5Li is analyzed. In the present investigation the nuclear width , nuclear cross-sections, astrophysical S-factor, and nuclear reaction rates have been computed. The present study is in better agreement with the observed data.
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Boran, S., and E. O. Kahya. "Testing a Dilaton Gravity Model Using Nucleosynthesis." Advances in High Energy Physics 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/282675.

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Big bang nucleosynthesis (BBN) offers one of the most strict evidences for theΛ-CDM cosmology at present, as well as the cosmic microwave background (CMB) radiation. In this work, our main aim is to present the outcomes of our calculations related to primordial abundances of light elements, in the context of higher dimensional steady-state universe model in the dilaton gravity. Our results show that abundances of light elements (primordial D,3He,4He, T, and7Li) are significantly different for some cases, and a comparison is given between a particular dilaton gravity model andΛ-CDM in the light
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Gai, M., E. E. Kading, M. Hass, et al. "The Interaction of Neutrons with 7Be at BBN Temperatures: Lack of Standard Nuclear Solution to the “Primordial 7Li Problem”." EPJ Web of Conferences 227 (2020): 01007. http://dx.doi.org/10.1051/epjconf/202022701007.

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We report the first measurement of alpha-particles from the interaction of neutrons with 7Be at “temperatures” of Big Bang Nucleosynthesis (BBN). We measured the Maxwellian averaged cross sections (MACS), with neutron beams produced by the LiLiT at the SARAF in Israel (with kT = 49.5 keV hence 0.57 GK). In addition, we measured the cross section of the 7Be(n,p) reaction, which is in excellent agreement with the recent measurement of the n_TOF collaboration, further substantiating our method as a demonstration of “proof of principle”. The cross section for the 7Be(n,ga) and the 7Be(n,a) reactio
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Reeves, Hubert. "Concluding Remarks II." Symposium - International Astronomical Union 198 (2000): 578–90. http://dx.doi.org/10.1017/s0074180900167361.

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The symposium has shown that our subject is well and very alive. It is progressing rapidly, thanks to a large amount of new observational data, obtained in particular by a young generation of competent astronomers. It is encouraging, incidentally, to note the large fraction of women in this generation. When I started in this field, some forty years ago, the feminine contribution was much smaller. I plan to review the state of the situation for each of the three nucleosynthesis processes responsible for the light elements: Big Bang Nucleosynthesis (BBN), galactic cosmic ray spallation of inters
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Pizzone, R. G., R. Spartá, M. La Cognata, et al. "Nuclear physics and its role for describing the early universe." International Journal of Modern Physics: Conference Series 49 (January 2019): 1960012. http://dx.doi.org/10.1142/s2010194519600127.

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Big Bang Nucleosynthesis (BBN) requires several nuclear physics inputs and nuclear reaction rates. An up-to-date compilation of direct cross sections of [Formula: see text], [Formula: see text]He and [Formula: see text]He reactions is given, being these ones among the most uncertain bare-nucleus cross sections. An intense experimental effort has been carried on in the last decade to apply the Trojan Horse Method (THM) to study reactions of relevance for the BBN and measure their astrophysical S(E)-factor. The reaction rates and the relative error for the four reactions of interest are then num
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KALITA, S., H. L. DUORAH, and K. DUORAH. "BIG BANG NUCLEOSYNTHESIS WITH A CONSTANT VACUUM ENERGY MOTIVATED BY CYCLIC COSMOLOGY." International Journal of Modern Physics A 26, no. 02 (2011): 331–39. http://dx.doi.org/10.1142/s0217751x11051275.

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Abundances of primordial deuterium, [Formula: see text] and helium, Yp, are examined by modifying the early universe expansion rate and hence the time–temperature relation, including a constant vacuum energy motivated by the cyclic scenario of brane cosmology. Enhancement of abundances with respect to standard BBN prediction is found. Rapid expansion leads to early freeze-out of weak interaction and hence to an enhanced neutron fraction at elevated freeze-out temperature, which in turn results in more helium. Nucleosynthesis at a much lower temperature (due to rapid expansion) faces a larger C
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LEE, LU-YUN, CHIA-MIN LIN, and CHIAN-SHU CHEN. "KINEMATICALLY BLOCKED CURVATON." Modern Physics Letters A 26, no. 36 (2011): 2731–37. http://dx.doi.org/10.1142/s0217732311037066.

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In this paper, we investigate the idea that the decay of a curvaton is kinematically blocked and show that the coupling constant for curvaton decay can be as large as [Formula: see text]. We also find in this case the lower bound of the Hubble parameter at horizon exit from big bang nucleosynthesis (BBN) is H* ≳ 7.2 × 10-9M P ~ 1010 GeV . Similar to conventional curvaton scenario, the nonlinear parameter can be as large as fNL = 100.
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Sasankan, N., Mayukh R. Gangopadhyay, G. J. Mathews, and M. Kusakabe. "Limits on brane-world and particle dark radiation from big bang nucleosynthesis and the CMB." International Journal of Modern Physics E 26, no. 08 (2017): 1741007. http://dx.doi.org/10.1142/s0218301317410075.

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The term dark radiation is used both to describe a noninteracting neutrino species and as a correction to the Friedmann Equation in the simplest five-dimensional (5D) RS-II brane-world cosmology. In this paper, we consider the constraints on both the meanings of dark radiation-based upon the newest results for light-element nuclear reaction rates, observed light-element abundances and the power spectrum of the Cosmic Microwave Background (CMB). Adding dark radiation during big bang nucleosynthesis (BBN) alters the Friedmann expansion rate causing the nuclear reactions to freeze out at a differ
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KANG, HO-SHIK. "PRIMORDIAL NUCLEOSYNTHESIS CONSTRAINTS ON NEUTRINO DEGENERACY." International Journal of Modern Physics D 02, no. 04 (1993): 381–400. http://dx.doi.org/10.1142/s0218271893000271.

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Based on the work by Kang and Steigman, I review the effects of neutrino degeneracy on big bang nucleosynthesis (BBN). Since the electron-neutrino degeneracy and the non-electron-neutrino degeneracy play a different role in the synthesis of the light elements ( D , 3 He , 4 He , 7 Li ), besides the baryon asymmetry (the nucleon-to-photon ratio; η ≡ nB/nγ) there are two additional free parameters in our scenario of degenerate BBN. An extended range of these parameters has been explored. It is shown that at a given η value, the agreement of the predicted primordial abundances of the light elemen
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Mossa, Viviana. "A BGO set-up for the direct measurement of the D(p,γ)3He fusion cross section at LUNA". Journal of Physics: Conference Series 1668, № 1 (2020): 012028. http://dx.doi.org/10.1088/1742-6596/1668/1/012028.

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Abstract The Big Bang Nucleosynthesis (BBN) describes the production of light nuclides occurred during the first minutes of cosmic time. It started with the accumulation of deuterium, whose primordial abundance is sensitive to the universal baryon density and to the amount of relativistic particles. Currently the main source of uncertainty to an accurate theoretical deuterium abundance evaluation is due to the poor knowledge of the D(p, γ)3He cross section at BBN energies. The present work wants to describe one of the two experimental approaches proposed by the LUNA collaboration, whose goal i
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Benetti, Micol, Salvatore Capozziello, and Gaetano Lambiase. "Updating constraints on f(T) teleparallel cosmology and the consistency with big bang nucleosynthesis." Monthly Notices of the Royal Astronomical Society 500, no. 2 (2020): 1795–805. http://dx.doi.org/10.1093/mnras/staa3368.

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ABSTRACT We focus on viable f(T) teleparallel cosmological models, namely power law, exponential, and square-root exponential, carrying out a detailed study of their evolution at all scales. Indeed, these models were extensively analysed in the light of late time measurements, while it is possible to find only upper limits looking at the very early time behaviour, i.e. satisfying the big bang nucleosynthesis (BBN) data on primordial abundance of 4He. Starting from these indications, we perform our analysis considering both background and linear perturbations evolution and constrain, beyond the
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Moscoso, Joseph, Rafael S. de Souza, Alain Coc та Christian Iliadis. "Bayesian Estimation of the D(p,γ)3He Thermonuclear Reaction Rate". Astrophysical Journal 923, № 1 (2021): 49. http://dx.doi.org/10.3847/1538-4357/ac1db0.

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Abstract Big bang nucleosynthesis (BBN) is the standard model theory for the production of light nuclides during the early stages of the universe, taking place about 20 minutes after the big bang. Deuterium production, in particular, is highly sensitive to the primordial baryon density and the number of neutrino species, and its abundance serves as a sensitive test for the conditions in the early universe. The comparison of observed deuterium abundances with predicted ones requires reliable knowledge of the relevant thermonuclear reaction rates and their corresponding uncertainties. Recent obs
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Park, Jubin, Chae-min Yun, Myung-Ki Cheoun, and Dukjae Jang. "Oscillating cosmic evolution and constraints on big bang nucleosynthesis in the extended Starobinsky model." Journal of Cosmology and Astroparticle Physics 2023, no. 05 (2023): 016. http://dx.doi.org/10.1088/1475-7516/2023/05/016.

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Abstract We investigate the cosmic evolutions in the extended Starobinsky model (eSM) obtained by adding one RabRab term to the Starobinsky model. We discuss the possibility of various cosmic evolutions with a special focus on the radiation-dominated era (RDE). Using simple assumptions, a second-order non-linear differential equation describing the various cosmic evolutions in the eSM is introduced. By solving this non-linear equation numerically, we show that the various cosmic evolutions, such as the standard cosmic evolution (a ∝ t 1/2) and a unique oscillating cosmic evolution, are feasibl
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Lucia Anna, Damone, N. Colonna, M. Barbagallo, et al. "7Be(n,p) cross section measurement for the Cosmological Lithium Problem at the n_TOF facility at CERN." EPJ Web of Conferences 184 (2018): 02004. http://dx.doi.org/10.1051/epjconf/201818402004.

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One of the most puzzling problems in Nuclear Astrophysics is the "Cosmological Lithium Problem", i.e the discrepancy between the primordial abundance of 7Li observed in metal poor halo stars [1], and the one predicted by Big Bang Nucleosynthesis (BBN). One of the reactions that could have an impact on the problem is 7Be(n,p)7Li. Despite of the importance of this reaction in BBN, the cross-section has never been directly measured at the energies of interest for BBN. Taking advantage of the innovative features of the second experimental area at the n_TOF facility at CERN, an accurate measurement
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37

Cavanna, Francesca. "Probing the early Universe from deep underground." EPJ Web of Conferences 260 (2022): 08005. http://dx.doi.org/10.1051/epjconf/202226008005.

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Big Bang Nucleosynthesis (BBN) occurs during the first minutes of cosmological time in a rapidly expanding hot and dense Universe, where a fraction of protons and nearly all free neutrons end up bound in 4He, while D, 3H, 3He, 6Li, 7Li and 7Be nuclei form in trace quantities. Among these elements, deuterium is an excellent indicator of cosmological parameters because its abundance is highly sensitive to the primordial baryon density and to the number of relativistic species. Although astronomical observations of primordial deuterium abundance have reached percent accuracy, theoretical predicti
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38

Amin, Mustafa A., Mark P. Hertzberg, David I. Kaiser, and Johanna Karouby. "Nonperturbative dynamics of reheating after inflation: A review." International Journal of Modern Physics D 24, no. 01 (2014): 1530003. http://dx.doi.org/10.1142/s0218271815300037.

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Our understanding of the state of the universe between the end of inflation and big bang nucleosynthesis (BBN) is incomplete. The dynamics at the end of inflation are rich and a potential source of observational signatures. Reheating, the energy transfer between the inflaton and Standard Model fields (possibly through intermediaries) and their subsequent thermalization, can provide clues to how inflation fits in with known high-energy physics. We provide an overview of our current understanding of the nonperturbative, nonlinear dynamics at the end of inflation, some salient features of realist
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39

Pizzone, R. G., and C. Spampinato. "The long-standing connection of BBN and Indirect measurements: The 3He(n,p)3H reaction at Big Bang energies." EPJ Web of Conferences 279 (2023): 01001. http://dx.doi.org/10.1051/epjconf/202327901001.

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Nuclear reactions play a key role in the framework of the Big Bang Nucleosynthesis. A network of 12 principal reactions has been identified as the main path which drives the elemental nucleosynthesis in the first twenty minutes of the history of the Universe. Among them an important role is played by neutron-induced reactions, which, from an experimental point of view, are usually a hard task to be measured directly. Nevertheless big efforts in the last decades have led to a better understanding of their role in the primordial nucleosynthesis network. In this work we apply the Trojan Horse Met
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40

Makki, T. R., and M. F. El Eid. "The lithium problem: new insight in the big bang nucleosynthesis (BBN) beyond the standard model." Journal of Physics: Conference Series 869 (June 2017): 012091. http://dx.doi.org/10.1088/1742-6596/869/1/012091.

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41

DI BARI, PASQUALE, PAOLO LIPARI та MAURIZIO LUSIGNOLI. "THE νμ↔νs INTERPRETATION OF THE ATMOSPHERIC NEUTRINO DATA AND COSMOLOGICAL CONSTRAINTS". International Journal of Modern Physics A 15, № 15 (2000): 2289–328. http://dx.doi.org/10.1142/s0217751x00000951.

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The data on atmospheric neutrinos can be explained assuming the existence of oscillations between νμ's and a light sterile neutrino with mixing close to maximal, and δm2~3×10-3 eV 2. This interpretation of the data is in potential conflict with the successes of big bang nucleosynthesis (BBN), since oscillations can result in a too large contribution of the sterile state to the energy density of the universe at the epoch of nucleosynthesis. The possibility to evade these cosmological constraints has been recently the object of some controversy. In this work we rediscuss this problem and find th
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42

Haro Cases, Jaume, and Llibert Aresté Saló. "The Spectrum of Gravitational Waves, Their Overproduction in Quintessential Inflation and Its Influence in the Reheating Temperature." Universe 6, no. 6 (2020): 87. http://dx.doi.org/10.3390/universe6060087.

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One of the most important issues in an inflationary theory as standard or quintessential inflation is the mechanism to reheat the universe after the end of the inflationary period in order to match with the Hot Big Bang universe. In quintessential inflation two mechanisms are frequently used, namely the reheating via gravitational particle production which is, as we will see, very efficient when the phase transition from the end of inflation to a kinetic regime (all the energy of the inflaton field is kinetic) is very abrupt, and the so-called instant preheating which is used for a very smooth
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43

Chichiri, Carlos, Graciela B. Gelmini, Philip Lu, and Volodymyr Takhistov. "Cosmological dependence of sterile neutrino dark matter with self-interacting neutrinos." Journal of Cosmology and Astroparticle Physics 2022, no. 09 (2022): 036. http://dx.doi.org/10.1088/1475-7516/2022/09/036.

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Abstract Unexplored interactions of neutrinos could be the key to understanding the nature of the dark matter (DM). In particular, active neutrinos with new self-interactions can produce keV-mass sterile neutrinos that account for the whole of the DM through the Dodelson-Widrow mechanism for a large range of active-sterile mixing values. This production typically occurs before Big-Bang Nucleosynthesis (BBN) in a yet uncharted era of the Universe. We assess how the mixing range for keV-mass sterile neutrino DM is affected by the uncertainty in the early Universe pre-BBN cosmology. This is parti
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44

Yeh, Tsung-Han, Jessie Shelton, Keith A. Olive, and Brian D. Fields. "Probing physics beyond the standard model: limits from BBN and the CMB independently and combined." Journal of Cosmology and Astroparticle Physics 2022, no. 10 (2022): 046. http://dx.doi.org/10.1088/1475-7516/2022/10/046.

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Abstract We present new Big Bang Nucleosynthesis (BBN) limits on the cosmic expansion rate or relativistic energy density, quantified via the number Nν of equivalent neutrino species. We use the latest light element observations, neutron mean lifetime, and update our evaluation for the nuclear rates d + d ⟶ 3He + n and d + d ⟶ 3H+ p. Combining this result with the independent constraints from the cosmic microwave background (CMB) yields tight limits on new physics that perturbs Nν and η prior to cosmic nucleosynthesis: a joint BBN+CMB analysis gives Nν = 2.898 ± 0.141, resulting in Nν < 3.1
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Mathews, Grant, Motohiko Kusakabe, Mayukh Gangopadhyay, Toshitaka Kajino, and Nishanth Sasankan. "Primordial Nucleosynthesis: Constraints on the Birth of the Universe." EPJ Web of Conferences 184 (2018): 01011. http://dx.doi.org/10.1051/epjconf/201818401011.

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We review the basic elements of big bang nucleosythesis (BBN) and how a comparison of predicted light-element abundances with observations constrains physics of the radiation-dominated epoch. We then summarize some applications of BBN and the cosmic microwave background (CMB) to constrain the first moments of the birth of the universe. In particular, we discuss how the existence of higher dimensions impacts the cosmic expansion through the projection of curvature from the higher dimension in the "dark radiation" term. We summarize current constraints from BBN and the CMB on this brane-world da
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46

KIRILOVA, DANIELA. "NEUTRINO SPECTRUM DISTORTION DUE TO OSCILLATIONS AND ITS BBN EFFECT." International Journal of Modern Physics D 13, no. 05 (2004): 831–41. http://dx.doi.org/10.1142/s0218271804004906.

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We study the distortion of electron neutrino energy spectrum due to oscillations with the sterile neutrino νe↔νs, for different initial populations of the sterile state δNs at the onset of oscillations. The influence of this spectrum distortion on Big Bang Nucleosynthesis is analyzed. Only the case of an initially empty sterile state was studied in previous publications. The primordial abundance of 4He is calculated for all possible δNs:0≤δNs≤1 in the model of oscillations, effective after electron neutrino decoupling, for which the spectrum distortion effects on the neutron–proton transitions
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KIRILOVA, DANIELA. "BBN CONSTRAINTS ON NEUTRINO OSCILLATIONS PARAMETERS RELAXED OR STRENGTHENED." International Journal of Modern Physics D 16, no. 07 (2007): 1197–210. http://dx.doi.org/10.1142/s0218271807010791.

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Big Bang Nucleosynthesis (BBN) with nonequilibrium νe ↔ νs oscillations, in the more general case of non-zero population of νs before oscillations δNs ≠ 0, is discussed. 4 He primordial production Yp(δNs) in the presence of νe ↔ νs oscillations for different initial populations of the sterile neutrino state 0 ≤ δ Ns ≤ 1 and the full range of oscillation parameters is calculated. Non-zero δNs has a two-fold effect on 4 He : (i) it enhances the energy density and hence increases the cosmic expansion rate, leading to Ypoverproduction, and (ii) it suppresses the kinetic effects of oscillations on
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48

Yang, X. J., and Aigen Li. "Deuterated Polycyclic Aromatic Hydrocarbons in the Interstellar Medium: The Aliphatic C–D Band Strengths." Astrophysical Journal Supplement Series 268, no. 1 (2023): 12. http://dx.doi.org/10.3847/1538-4365/ace4c6.

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Abstract Deuterium (D) was exclusively generated in the Big Bang, and the standard Big Bang nucleosynthesis (BBN) model predicts a primordial abundance of D/H ≈ 26 parts per million (ppm). As the Galaxy evolves, D/H gradually decreases because of astration. The Galactic chemical evolution (GCE) model predicts a present-day abundance of D/H ≳ 20 ppm. However, observations of the local interstellar medium have revealed that the gas-phase interstellar D/H varies considerably from one region to another and has a median abundance of D/H ≈ 13 ppm, substantially lower than predicted from the BBN and
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49

Zhou, Yi. "Methods of Discovering New Physics from the Cosmic Neutrino Background." Journal of Physics: Conference Series 2381, no. 1 (2022): 012079. http://dx.doi.org/10.1088/1742-6596/2381/1/012079.

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Abstract Neutrinos play a significant role in the thermal history of the early universe. The standard cosmological model predicts a relic sea of neutrinos, often referred to as the Cosmic Neutrino Background (CNB). The effects of CNB are parameterized as the effective number of neutrino flavors N eff, which could be measured by indirect astronomy observations. The numerical calculations of the neutrino decoupling process give a result of N eff = 3.046. To measure it with astronomy observations, the primordial abundance of elements from the Big Bang Nucleosynthesis (BBN) and the anisotropies in
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50

Kantha, L. "A Time-DependentΛandGCosmological Model Consistent with Cosmological Constraints". Advances in Astronomy 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/9743970.

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The prevailing constantΛ-Gcosmological model agrees with observational evidence including the observed red shift, Big Bang Nucleosynthesis (BBN), and the current rate of acceleration. It assumes that matter contributes 27% to the current density of the universe, with the rest (73%) coming from dark energy represented by the Einstein cosmological parameterΛin the governing Friedmann-Robertson-Walker equations, derived from Einstein’s equations of general relativity. However, the principal problem is the extremely small value of the cosmological parameter (~10−52 m2). Moreover, the dark energy d
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