scholarly journals (Non-)Thermal Production of WIMPs during Kination

Symmetry ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 546 ◽  
Author(s):  
Luca Visinelli
Keyword(s):  
Big Bang ◽  
Weakly Interacting Massive Particles ◽  
Beyond The Standard Model ◽  
Big Bang Nucleosynthesis ◽  
Yield Information ◽  
Cosmological Scenario ◽  
The Standard Model ◽  
Direct Data ◽  
The Subject ◽  
The Universe

Understanding the nature of the Dark Matter (DM) is one of the current challenges in modern astrophysics and cosmology. Knowing the properties of the DM particle would shed light on physics beyond the Standard Model and even provide us with details of the early Universe. In fact, the detection of such a relic would bring us information from the pre-Big Bang Nucleosynthesis (BBN) period, an epoch from which we have no direct data, and could even hint at inflation physics. In this work, we assume that the expansion rate of the Universe after inflation is governed by the kinetic energy of a scalar field ϕ , in the so-called “kination” model. Adding to previous work on the subject, we assume that the ϕ field decays into both radiation and DM particles, which we take to be Weakly Interacting Massive Particles (WIMPs). The present abundance of WIMPs is then fixed during the kination period through either a thermal “freeze-out” or “freeze-in” mechanism, or through a non-thermal process governed by the decay of ϕ . We explore the parameter space of this theory with the requirement that the present WIMP abundance provides the correct relic budget. Requiring that BBN occurs during the standard cosmological scenario sets a limit on the temperature at which the kination period ends. Using this limit and assuming the WIMP has a mass m χ = 100 GeV, we obtain that the thermally averaged WIMP annihilation cross section has to satisfy the constraints 4 × 10 − 16 GeV − 2 ≲ ⟨ σ v ⟩ ≲ 2 × 10 − 5 GeV − 2 in order for having at least one of the production mechanism to yield the observed amount of DM. This result shows how the properties of the WIMP particle, if ever measured, can yield information on the pre-BBN content of the Universe.

scholarly journals (Non-)Thermal Production of WIMPs during Kination

2018 ◽  
Author(s):  
Luca Visinelli
Keyword(s):  
Cross Section ◽  
Big Bang ◽  
Weakly Interacting Massive Particles ◽  
Beyond The Standard Model ◽  
Big Bang Nucleosynthesis ◽  
Yield Information ◽  
Cosmological Scenario ◽  
The Standard Model ◽  
The Universe ◽  
Shed Light

Understanding the nature of the Dark Matter (DM) is one of the current challenges in modern astrophysics and cosmology. Knowing the properties of the DM particle would shed light on physics beyond the Standard Model and even provide us with details of the early Universe. In fact, the detection of such a relic would bring us information from the pre-Big Bang Nucleosynthesis (BBN) period, an epoch from which we have no data, and could even hint at inflationary physics. In this work, we assume that the expansion rate of the Universe after inflationary is governed by the kinetic energy of a scalar field ϕ, in the so-called “kination” model. We assume that the ϕ field decays into both radiation and DM particles, which we take to be Weakly Interacting Massive Particles (WIMPs). The present abundance of WIMPs is then fixed during the kination period through either a thermal “freeze-out” or “freeze-in” mechanism, or through a non-thermal process governed by the decay of ϕ. We explore the parameter space of this theory with the requirement that the present WIMP abundance provides the correct DM relic budget. Requiring that BBN occurs during the standard cosmological scenario sets a limit on the temperature at which the kination period ends. Using this limit and assuming the WIMP has a mass mχ = 100 GeV, we obtain that the thermally-averaged WIMP annihilation cross section has to satisfy the constraints 3.5 × 10−16 GeV−2 ≲ (σv) ≲ 1.4 × 10−5 GeV−2 in order for having at least one of the production mechanism to yield the observed amount of DM. This result shows how the properties of the WIMP particle, if ever measured, can yield information on the pre-BBN content of the Universe.

scholarly journals An allowed window for heavy neutral leptons below the kaon mass

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Kyrylo Bondarenko ◽  
Alexey Boyarsky ◽  
Juraj Klaric ◽  
Oleksii Mikulenko ◽  
Oleg Ruchayskiy ◽  
...  
Keyword(s):  
Standard Model ◽  
Parameter Space ◽  
Big Bang ◽  
Majorana Fermions ◽  
Neutrino Masses ◽  
Beyond The Standard Model ◽  
Big Bang Nucleosynthesis ◽  
Kaon Mass ◽  
The Standard Model ◽  
The Universe

Abstract The extension of the Standard Model with two gauge-singlet Majorana fermions can simultaneously explain two beyond-the-Standard-model phenomena: neutrino masses and oscillations, as well as the origin of the matter-antimatter asymmetry in the Universe. The parameters of such a model are constrained by the neutrino oscillation data, direct accelerator searches, big bang nucleosynthesis, and requirement of successful baryogenesis. We show that their combination still leaves an allowed region in the parameter space below the kaon mass. This region can be probed by the further searches of NA62, DUNE, or SHiP experiments.

IS A 17 keV NEUTRINO COMPATIBLE WITH SUPERNOVA AND NUCLEOSYNTHESIS CONSTRAINTS?

1992 ◽  
Vol 07 (10) ◽  
pp. 821-834
Author(s):  
I. Z. ROTHSTEIN
Keyword(s):  
Standard Model ◽  
Big Bang ◽  
Beyond The Standard Model ◽  
Big Bang Nucleosynthesis ◽  
The Standard Model ◽  
Work Done

In this article I review the work done on accommodating a 17 keV neutrino. Special emphasis is paid to supernova and big-bang nucleosynthesis constraints since, when in tandem, they are particularly insidious. It is shown that a 17 keV neutrino is compatible with the constraints, but that it is necessary to go well beyond the standard model to evade them.

scholarly journals Big Bang Nucleosynthesis in Visible and Hidden-Mirror Sectors

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Paolo Ciarcelluti
Keyword(s):  
Dark Matter ◽  
Building Blocks ◽  
Big Bang ◽  
Dark Matter Candidate ◽  
Big Bang Nucleosynthesis ◽  
Enhanced Production ◽  
The Standard Model ◽  
The Big Bang ◽  
The Universe ◽  
Mirror Matter

One of the still viable candidates for the dark matter is the so-called mirror matter. Its cosmological and astrophysical implications were widely studied, pointing out the importance to go further with research. In particular, the Big Bang nucleosynthesis provides a strong test for every dark matter candidate, since it is well studied and involves relatively few free parameters. The necessity of accurate studies of primordial nucleosynthesis with mirror matter has then emerged. I present here the results of accurate numerical simulations of the primordial production of both ordinary nuclides and nuclides made of mirror baryons, in presence of a hidden mirror sector with unbroken parity symmetry and with gravitational interactions only. These elements are the building blocks of all the structures forming in the Universe; therefore, their chemical composition is a key ingredient for astrophysics with mirror dark matter. The production of ordinary nuclides shows differences from the standard model for a ratio of the temperatures between mirror and ordinary sectorsx=T′/T≳0.3, and they present an interesting decrease of the abundance ofLi7. For the mirror nuclides, instead, one observes an enhanced production ofHe4, which becomes the dominant element forx≲0.5, and much larger abundances of heavier elements.

BIG BANG NUCLEOSYNTHESIS: AN UPDATE

1996 ◽  
Vol 11 (03) ◽  
pp. 409-428 ◽  
Author(s):  
KEITH A. OLIVE ◽  
SEAN T. SCULLY
Keyword(s):  
Standard Model ◽  
Light Element ◽  
Big Bang ◽  
Current Status ◽  
Beyond The Standard Model ◽  
Effective Number ◽  
Big Bang Nucleosynthesis ◽  
Element Abundances ◽  
The Standard Model

The current status of big bang nucleosynthesis is reviewed with an emphasis on the comparison between the observational determination of the light element abundances of D , 3 He , 4 He and 7 Li and the predictions from theory. In particular, we present new analyses for 4 He and 7 Li . Implications for physics beyond the standard model are also discussed. In addition, limits on the effective number of neutrino flavors are updated.

scholarly journals Relativistic Cosmology with an Introduction to Inflation

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 276
Author(s):  
Muhammad Zahid Mughal ◽  
Iftikhar Ahmad ◽  
Juan Luis García Guirao
Keyword(s):  
Standard Model ◽  
Early Universe ◽  
Large Scale ◽  
Initial Conditions ◽  
Big Bang ◽  
Relativistic Cosmology ◽  
The Standard Model ◽  
Big Bang Model ◽  
The Big Bang ◽  
The Universe

In this review article, the study of the development of relativistic cosmology and the introduction of inflation in it as an exponentially expanding early phase of the universe is carried out. We study the properties of the standard cosmological model developed in the framework of relativistic cosmology and the geometric structure of spacetime connected coherently with it. The geometric properties of space and spacetime ingrained into the standard model of cosmology are investigated in addition. The big bang model of the beginning of the universe is based on the standard model which succumbed to failure in explaining the flatness and the large-scale homogeneity of the universe as demonstrated by observational evidence. These cosmological problems were resolved by introducing a brief acceleratedly expanding phase in the very early universe known as inflation. The cosmic inflation by setting the initial conditions of the standard big bang model resolves these problems of the theory. We discuss how the inflationary paradigm solves these problems by proposing the fast expansion period in the early universe. Further inflation and dark energy in fR modified gravity are also reviewed.

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