The new hybrid BBN model with the photon cooling, X particle, and the primordial magnetic field

Yamazaki, Dai; Kusakabe, Motohiko; Kajino, Toshitaka; Mathews, Grant J.; Cheoun, Myung-Ki

doi:10.1142/s0218301317410063

Cited by 11 publications

(6 citation statements)

References 64 publications

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“…Many such attempts exist in the literature, so far without success. Examples of mechanisms considered include scalar-tensor theories, photon cooling, early-or late-time decaying particles (including decaying dark matter, or magnetic fields [642,[1726][1727][1728][1729][1730][1731][1732][1733][1734][1735][1736][1737][1738]. They either fail by being incompatible with other constraints, require strong finetuning, or can only alleviate the problem (e.g., by increasing the error bars for the theoretically expected abundances).…”

Section: The Lithium Problemmentioning

confidence: 99%

Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies

Abdalla,

Abellán,

Aboubrahim

et al. 2022

Preprint

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This White Paper has been prepared to fulfill SNOWMASS 2021 requirements and it extends the material previously summarized in the four Letters of Interest [1][2][3][4]. The Particle Physics Community Planning Exercise (a.k.a. SNOWMASS ) is organized by the Division of Particles and Fields of the American Physical Society, and this is an effort to bring together the community of theoretical physicists and cosmologists and identify promising opportunities to address the questions described.This White Paper was initiated with the aim of identifying the opportunities in the cosmological field for the next decade, and strengthening the coordination of the community. It is addressed to identifying the most promising directions of investigation, and rather than attempting a long review of the current status of the whole field of research, it focuses on the upcoming theoretical opportunities and challenges described. The White Paper is a collaborative effort led by Eleonora Di Valentino and Luis Anchordoqui, and it is organized in the topics listed below, each of them coordinated by the scientists indicated (alphabetical order):

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Section: The Lithium Problemmentioning

confidence: 99%

Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies

Abdalla,

Abellán,

Aboubrahim

et al. 2022

Preprint

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“…A number of recent papers have addressed this problem [6,13,14,[23][24][25][26][27][28][29]. At present it is not yet known if this discrepancy derives from a destruction of lithium on the old stars used to deduce the primordial lithium abundance, or if it requires exotic new physics in the early universe [13,14,23,24,26], or even a modification of the particle statistics in BBN itself [27,28]. In this paper, we summarize some recent work and their prospects for solving the lithium problem.…”

Section: Lithium Abundancementioning

confidence: 99%

“…In view of the difficulty of consistently overproducing D/H in models that attempt to reduct the 7 Li production, there have been some attempts [26,29] to apply hybrid models involving multiple simultaneous extensions of the standard BBN model. The essence of this approach is to use one extension to deplete 7 Li and another to restore D/H to the observed value.…”

Section: Hybrid Modelsmentioning

confidence: 99%

“…The essence of this approach is to use one extension to deplete 7 Li and another to restore D/H to the observed value. For example, in [25,26] it was shown that the simultaneous imposition of photon cooling after BBN, plus X-particle decay, plus a primordial magnetic field could satisfy the D/H and 7 Li constraints, but at the cost of overproducing 6 Li. Alternatively in [29] the right combinations of varying: the neutrino temperatures; neutrino chemical potentials; number of neutrino species; plus photon cooling; and/or a form of unified dark matter, could help to alleviate (but not completely resolve) the lithium problem.…”

Section: Hybrid Modelsmentioning

confidence: 99%

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Cosmological Solutions to the Lithium Problem

Mathews

Kedia

Sasankan

et al. 2020

Proceedings of the 15th International Symposium on Origin of Matter and Evolution of Galaxies (OMEG15)

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The abundance of primordial lithium is derived from the observed spectroscopy of metal-poor stars in the galactic halo. However, the observationally inferred abundance remains at about a factor of three below the abundance predicted by standard big bang nucleosynthesis (BBN). The resolution of this dilemma can be either astrophysical (stars destroy lithium after BBN), nuclear (reactions destroy lithium during BBN), or cosmological, i.e. new physics beyond the standard BBN is responsible for destroying lithium. Here, we overview a variety of possible cosmological solutions, and their shortcomings. On the one hand, we examine the possibility of physical processes that modify the velocity distribution of particles from the usually assumed Maxwell-Boltzmann statistics. A physical justification for this is an inhomogeneous spatial distribution of domains of primordial magnetic field strength as a means to reduce the primordial lithium abundance. Another possibility is that scattering with the mildly relativistic electrons in the background plasma alters the baryon distribution to one resembling a Fermi-Dirac distribution. We show that neither of these possibilities can adequately resolve the lithium problem. A number of alternate hybrid models are discussed including a mix of neutrino degeneracy, unified dark matter, axion cooling, and the presence of decaying and/or charged supersymmetric particles.

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“…A number of recent papers have addressed this problem [13,14,[25][26][27][28]. At present it is not yet known if this discrepancy derives from a destruction of Lithium on the old stars used to deduce the primordial Lithium abundance, or if it requires exotic new physics in the early universe [13,14,[25][26][27], or even a modification of the particle statistics in BBN itself [28]. For the remainder of this introduction we will adopt the premise that this disagreement may indicate new physics in the early universe.…”

Section: Comparison Of Bbn With Observed Abundancesmentioning

confidence: 99%

Primordial Nucleosynthesis: Constraints on the Birth of the Universe

et al. 2018

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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 dark radiation term. At the same time, the existence of extra dimensions during the earlier inflation impacts the tensor to scalar ratio and the running spectral index as measured in the CMB. We summarize how the constraints on inflation shift when embedded in higher dimensions. Finally, one expects that the universe was born out of a complicated multiverse landscape near the Planck time. In these moments the energy scale of superstrings was obtainable during the early moments of chaotic inflation. We summarize the quest for cosmological evidence of the birth of space-time out of the string theory landscape. We will explore the possibility that a superstring excitations may have made itself known via a coupling to the field of inflation. This may have left an imprint of "dips" in the power spectrum of temperature fluctuations in the cosmic microwave background. The identification of this particle as a superstring is possible because there may be evidence for different oscillator states of the same superstring that appear on different scales on the sky. It will be shown that from this imprint one can deduce the mass, number of oscillations, and coupling constant for the superstring. Although the evidence is marginal, this may constitute the first observation of a superstring in Nature.

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The new hybrid BBN model with the photon cooling, X particle, and the primordial magnetic field

Cited by 11 publications

References 64 publications

Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies

Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies

Cosmological Solutions to the Lithium Problem

Primordial Nucleosynthesis: Constraints on the Birth of the Universe

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