scholarly journals Higgsino dark matter in a non-standard history of the universe

2019 ◽  
Vol 798 ◽  
pp. 134997
Author(s):  
Chengcheng Han
Keyword(s):  
Dark Matter ◽  
History Of ◽  
The Universe

scholarly journals Displaced new physics at colliders and the early universe before its first second

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Lorenzo Calibbi ◽  
Francesco D’Eramo ◽  
Sam Junius ◽  
Laura Lopez-Honorez ◽  
Alberto Mariotti
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Upper Bound ◽  
New Physics ◽  
Early History ◽  
Relic Density ◽  
History Of ◽  
Indirect Information ◽  
The Universe

Abstract Displaced vertices at colliders, arising from the production and decay of long-lived particles, probe dark matter candidates produced via freeze-in. If one assumes a standard cosmological history, these decays happen inside the detector only if the dark matter is very light because of the relic density constraint. Here, we argue how displaced events could very well point to freeze-in within a non-standard early universe history. Focusing on the cosmology of inflationary reheating, we explore the interplay between the reheating temperature and collider signatures for minimal freeze-in scenarios. Observing displaced events at the LHC would allow to set an upper bound on the reheating temperature and, in general, to gather indirect information on the early history of the universe.

scholarly journals A dark clue to seesaw and leptogenesis in a pseudo-Dirac singlet doublet scenario with (non)standard cosmology

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Partha Konar ◽  
Ananya Mukherjee ◽  
Abhijit Kumar Saha ◽  
Sudipta Show
Keyword(s):  
Dark Matter ◽  
Thermal History ◽  
Direct Detection ◽  
Critical Role ◽  
Mass Term ◽  
Baryon Asymmetry ◽  
Dark Sector ◽  
Lepton Asymmetry ◽  
History Of ◽  
The Universe

Abstract We propose an appealing alternative scenario of leptogenesis assisted by dark sector which leads to the baryon asymmetry of the Universe satisfying all theoretical and experimental constraints. The dark sector carries a non minimal set up of singlet doublet fermionic dark matter extended with copies of a real singlet scalar field. A small Majorana mass term for the singlet dark fermion, in addition to the typical Dirac term, provides the more favourable dark matter of pseudo-Dirac type, capable of escaping the direct search. Such a construction also offers a formidable scope to radiative generation of active neutrino masses. In the presence of a (non)standard thermal history of the Universe, we perform the detailed dark matter phenomenology adopting the suitable benchmark scenarios, consistent with direct detection and neutrino oscillations data. Besides, we have demonstrated that the singlet scalars can go through CP-violating out of equilibrium decay, producing an ample amount of lepton asymmetry. Such an asymmetry then gets converted into the observed baryon asymmetry of the Universe through the non-perturbative sphaleron processes owing to the presence of the alternative cosmological background considered here. Unconventional thermal history of the Universe can thus aspire to lend a critical role both in the context of dark matter as well as in realizing baryogenesis.

scholarly journals Dark Stars: Dark matter in the first stars leads to a new phase of stellar evolution

2008 ◽  
Vol 4 (S255) ◽  
pp. 56-60 ◽  
Author(s):  
Katherine Freese ◽  
Douglas Spolyar ◽  
Anthony Aguirre ◽  
Peter Bodenheimer ◽  
Paolo Gondolo ◽  
...  
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Cross Section ◽  
Stellar Evolution ◽  
Weakly Interacting Massive Particles ◽  
First Stars ◽  
History Of ◽  
Born Again ◽  
The Universe ◽  
New Phase

AbstractThe first phase of stellar evolution in the history of the universe may be Dark Stars, powered by dark matter heating rather than by fusion. Weakly interacting massive particles, which are their own antiparticles, can annihilate and provide an important heat source for the first stars in the the universe. This talk presents the story of these Dark Stars. We make predictions that the first stars are very massive (~800M⊙), cool (6000 K), bright (~106L⊙), long-lived (~106years), and probable precursors to (otherwise unexplained) supermassive black holes. Later, once the initial DM fuel runs out and fusion sets in, DM annihilation can predominate again if the scattering cross section is strong enough, so that a Dark Star is born again.

scholarly journals Dark Matter Realism

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Niels C. M. Martens
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Logical Empiricism ◽  
Mass Energy ◽  
Current State ◽  
The Standard Model ◽  
Luminous Matter ◽  
History Of ◽  
The Universe ◽  
Current Stage

AbstractAccording to the standard model of cosmology, $$\Lambda $$ Λ CDM, the mass-energy budget of the current stage of the universe is not dominated by the luminous matter that we are familiar with, but instead by some form of dark matter (and dark energy). It is thus tempting to adopt scientific realism about dark matter. However, there are barely any constraints on the myriad of possible properties of this entity—it is not even certain that it is a form of matter. In light of this underdetermination I advocate caution: we should not (yet) be dark matter realists. The “not(-yet)-realism” that I have in mind is different from Hacking’s (Philos Sci 56 (4), 555–581, 1989) anti-realism, in that it is semantic rather than epistemological. It also differs from the semantic anti-realism of logical empiricism, in that it is naturalistic, such that it may only be temporary and does not automatically apply to all other unobservables (or even just to all other astronomical unobservables, as with Hacking’s anti-realism). The argument is illustrated with the analogy of the much longer history of the concept of a gene, as the current state of the concept of dark matter resembles in some relevant ways that of the early concept of genes.

5. Cosmology

2017 ◽  
pp. 58-82
Author(s):  
Timothy Clifton
Keyword(s):  
Dark Matter ◽  
Large Scale ◽  
Gravitational Interaction ◽  
Albert Einstein ◽  
Scientific Discipline ◽  
Normal Matter ◽  
History Of Cosmology ◽  
History Of ◽  
Edwin Hubble ◽  
The Universe

Cosmology began as a scientific discipline at the beginning of the 20th century, with the work of Albert Einstein and Edwin Hubble. Gravitational interaction is fundamental to cosmology, as gravity dominates over all other forces on large-scale distances. ‘Cosmology’ outlines the modern history of cosmology, discussing how studies have provided knowledge on the early Universe and its expansion. The Concordance Model proposes that only c.5 per cent of the energy in the Universe is in the form of normal matter; c.25 per cent is in the form of the gravitationally attractive dark matter; and the remaining c.70 per cent is in the form of the gravitationally repulsive dark energy. But there is still much to learn.

How to constrain warm dark matter with the Lyman-α forest

2021 ◽  
Vol 502 (2) ◽  
pp. 2356-2363
Author(s):  
Antonella Garzilli ◽  
Andrii Magalich ◽  
Oleg Ruchayskiy ◽  
Alexey Boyarsky
Keyword(s):  
Dark Matter ◽  
High Resolution ◽  
Power Spectrum ◽  
Systematic Uncertainty ◽  
Thermal Effects ◽  
Specific Class ◽  
Small Scales ◽  
History Of ◽  
The Universe

ABSTRACT The flux power spectrum (FPS) of the high-resolution Lyman-α forest data exhibits suppression at small scales. The origin of this suppression can be due to long-sought warm dark matter (WDM) or to thermal effects, related to the largely unknown reionization history of the Universe. Previous works explored a specific class of reionization histories that exhibit sufficiently strong thermal suppression and leave little room for WDM interpretation. In this work, we choose a different class of reionization histories, fully compatible with available data on evolution of reionization, but much colder than the reionization histories used by previous authors in determining the nature of dark matter, thus leaving the broadest room for the WDM interpretation of the suppression in the FPS. We find that WDM thermal relics with masses below 1.9 keV (95 per cent CL) would produce a suppression at scales that are larger than observed maximum of the FPS, independently of assumptions about thermal effects. This WDM mass is significantly lower than previously claimed bounds, demonstrating the level of systematic uncertainty of the Lyman-α forest method, due to the previous modelling. We also discuss how this uncertainty may affect also data at large scales measured by eBOSS(Baryon Oscillation Spectroscopic Survey).

scholarly journals Accelerated expansion of the Universe in the presence of dark matter pressure

2020 ◽  
Vol 98 (2) ◽  
pp. 210-216
Author(s):  
Zeinab Rezaei
Keyword(s):  
Dark Matter ◽  
Equation Of State ◽  
Hubble Parameter ◽  
Energy Equation ◽  
Accelerated Expansion ◽  
Luminosity Distance ◽  
Modern Cosmology ◽  
History Of ◽  
Expansion Of The Universe ◽  
The Universe

Expansion dynamics of the Universe is an important subject in modern cosmology. The dark energy equation of state determines these dynamics so that the Universe is in an accelerating phase. However, dark matter (DM) can also affect the accelerated expansion of the Universe through its equation of state. In the present work, we explore the expansion dynamics of the Universe in the presence of DM pressure. In this regard, applying the DM equation of state from the observational data related to the rotational curves of galaxies, we calculate the evolution of DM density. Moreover, the Hubble parameter, history of scale factor, luminosity distance, and deceleration parameter are studied while the DM pressure is taken into account. Our results verify that the DM pressure leads to higher values of the Hubble parameter at each redshift and the expansion of the Universe grows due to the DM pressure.

scholarly journals Warm dark matter and the ionization history of the Universe

2017 ◽  
Vol 96 (10) ◽  
Author(s):  
Laura Lopez-Honorez ◽  
Olga Mena ◽  
Sergio Palomares-Ruiz ◽  
Pablo Villanueva-Domingo
Keyword(s):  
Dark Matter ◽  
History Of ◽  
The Universe

scholarly journals CRÍTICA DE CHOMSKY AO MATERIALISMO

2012 ◽  
Vol 3 (6) ◽  
pp. 18-26
Author(s):  
Daniel Luporini de Faria
Keyword(s):  
Dark Matter ◽  
Philosophy Of Mind ◽  
Natural Sciences ◽  
Normal Science ◽  
Ontological Status ◽  
Mechanical Philosophy ◽  
Noam Chomsky ◽  
History Of ◽  
The Mind ◽  
The Universe

No presente artigo, pretende-se expor e analisar as críticas que Noam Chomsky (2000) dirige contra o materialismo em filosofia da mente. Para o referido autor, a rigor, não faria sentido questionar o estatuto ontológico da mente, na medida em que os próprios físicos e filósofos materialistas desconhecem 90% da matéria que constitui o universo (a matéria e energia escuras). Deste modo, Chomsky dirá que no tempo de Descartes, da filosofia mecânica, o que se fazia era ciência normal, ao passo que após o advento das ideias de Newton, o universo passa a ser antimaterialista. O presente trabalho pode ser útil/valioso à filosofia e história das ciências naturais, à física e à filosofia da mente. Palavras-chave: Materialismo; Matéria Escura; Filosofia Mecânica.   Abstract The aim of this paper is to expose and analyze Noam Chomsky’s criticisms against materialism in philosophy of mind. For this author, strictly speaking, questioning the ontological status of the mind would not make sense, considering that the materialistic physicists and philosophers themselves are unaware of 90% of the matter that constitutes the universe (dark matter and energy). Accordingly, Chomsky will say that in Descartes’ time, or in times of mechanical philosophy, what was done was normal science, while after the advent of Newton's ideas the universe becomes anti-materialist. This paper can be useful/valuable to philosophy and history of natural sciences, physics and philosophy of mind. Keywords: Materialism; Dark Matter; Mechanical Philosophy.

scholarly journals Revisiting CMB constraints on dark matter annihilation

2021 ◽  
Vol 2021 (12) ◽  
pp. 015
Author(s):  
Masahiro Kawasaki ◽  
Hiromasa Nakatsuka ◽  
Kazunori Nakayama ◽  
Toyokazu Sekiguchi
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Annihilation Cross Section ◽  
Precision Measurements ◽  
Microwave Background ◽  
Dark Matter Annihilation ◽  
Simulation Code ◽  
Strong Constraint ◽  
History Of ◽  
The Universe

Abstract The precision measurements of the cosmic microwave background power spectrum put a strong constraint on the dark matter annihilation cross section since the electromagnetic energy injection by the dark matter annihilation affects the ionization history of the universe. In this paper, we update our previous simulation code for calculating the ionization history with the effect of dark matter annihilation by including Helium interactions and improving the precision of calculations. We give an updated constraint on the annihilation cross section and mass of dark matter using the modified RECFAST code with the Planck 2018 datasets.

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