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Related papers: Fermi-Dirac corrections to relic abundances

200 papers

Although Planck data supports the standard \Lambda CDM model, it still allows for the presence of Dark Radiation corresponding up to about half an extra standard neutrino species. We propose a scenario for obtaining a fractional "effective…

High Energy Physics - Phenomenology · Physics 2015-06-15 Pasquale Di Bari , Stephen F. King , Alexander Merle

We show that a thermal relic which decouples from the standard model (SM) plasma while relativistic can be a viable dark matter (DM) candidate, if the decoupling is followed by a period of entropy dilution that heats up the SM, but not the…

High Energy Physics - Phenomenology · Physics 2020-03-18 Jared A. Evans , Akshay Ghalsasi , Stefania Gori , Michele Tammaro , Jure Zupan

We analyze how the thermal history of the universe is influenced by the statistical description, assuming a deviation from the usual Bose-Einstein, Fermi-Dirac and Boltzmann-Gibbs distribution functions. These deviations represent the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 M. E. Pessah , Diego F. Torres , H. Vucetich

The optical properties of plasmas with high densities and medium temperatures are analyzed by the use of a free electron model with Fermi-Dirac statistics. For the present collisional plasma the frequency of electron-ion collision is very…

Instrumentation and Methods for Astrophysics · Physics 2018-09-05 Y. Ben-Aryeh

Precision measurements of the number of effective relativistic neutrino species and the primordial element abundances require accurate theoretical predictions for early Universe observables in the Standard Model and beyond. Given the…

High Energy Physics - Phenomenology · Physics 2020-05-28 Miguel Escudero

We present a renormalization group analysis of the disorder effects on the low-energy behaviors of twodimensional tilted Dirac-fermion systems, in which the fermions have two distinct orbitals unrelated by any symmetry. Four types of…

Disordered Systems and Neural Networks · Physics 2018-08-31 Peng-Lu Zhao , An-Min Wang , Guo-Zhu Liu

We demonstrate that if the dark matter (DM) in the Universe contains multiple components,the interactions between the DM components may induce DM conversions. It is then possible that the lightest DM component with an annihilation cross…

High Energy Physics - Phenomenology · Physics 2011-10-11 Ze-Peng Liu , Yue-Liang Wu , Yu-Feng Zhou

We solve the nonequilibrium dynamics of a 3+1 dimensional theory with Dirac fermions coupled to scalars via a chirally invariant Yukawa interaction. The results are obtained from a systematic coupling expansion of the 2PI effective action…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. Berges , Sz. Borsanyi , J. Serreau

We develop a unified description of dense fermionic matter that consistently incorporates Pauli degeneracy, interaction effects, and pairing correlations. The condition that the temperature is much smaller than the Fermi energy leads to a…

High Energy Physics - Phenomenology · Physics 2026-05-05 Yaroslav D. Krivenko-Emetov , Gleb Shabal

In the framework of the standard, hot big bang cosmological model the dynamics of the early evolution of the universe is controlled by the energy density of relativistic particles, among which neutrinos play an important role. In…

Astrophysics · Physics 2007-05-23 Gary Steigman

The Fermi polaron problem, which describes a mobile impurity that interacts with a spin-polarized Fermi sea, is a paradigmatic system in quantum many-body physics and has been challenging to address quantitatively in its strong coupling…

Quantum Gases · Physics 2025-11-26 S. Ramachandran , S. Jensen , Y. Alhassid

We study the thermal evolution of a highly spin-imbalanced, homogeneous Fermi gas with unitarity limited interactions, from a Fermi liquid of polarons at low temperatures to a classical Boltzmann gas at high temperatures. Radio-frequency…

The formation of topological defects in a second order phase transition in the early universe is an out-of-equilibrium process. Condensed matter experiments seem to support Zurek's mechanism, in which the freezing of thermal fluctuations…

High Energy Physics - Phenomenology · Physics 2007-05-23 Massimo Pietroni

Uniform semiclassical approximations for the number and kinetic-energy densities are derived for many non-interacting fermions in one-dimensional potentials with two turning points. The resulting simple, closed-form expressions contain the…

Quantum Physics · Physics 2015-02-26 Raphael F. Ribeiro , Donghyung Lee , Attila Cangi , Peter Elliott , Kieron Burke

We sketch the average behaviour of the temperatures and densities of the main components of the $\Lambda$CDM universe after inflation. It is modelled as a perfect fluid with dark energy associated with the macroscopic effect of conformal…

High Energy Physics - Phenomenology · Physics 2014-10-15 Natacha Leite , Alex H. Blin

The complete lack of theoretical understanding of the quantum critical states found in the heavy fermion metals and the normal states of the high-T$_c$ superconductors is routed in deep fundamental problem of condensed matter physics: the…

Strongly Correlated Electrons · Physics 2008-07-08 Frank Krüger , Jan Zaanen

This paper provides a systematic and complete study of thermal field theory with fermion fields of any kind for generic equilibrium density matrices, which feature arbitrary values not only of temperature and chemical potentials, but also…

High Energy Physics - Phenomenology · Physics 2026-05-19 Alberto Salvio

It is shown, in the framework of the Thomas-Fermi model at finite temperature, that a cooling non-degenerate gas of massive neutrinos will, at a certain temperature, become unstable and undergo a first-order phase transition in which…

Astrophysics · Physics 2007-05-23 Neven Bilic , Raoul D. Viollier

We relate the Fermi-Dirac statistics of an ideal Fermi gas in a harmonic trap to partitions of given integers into distinct parts, studied in number theory. Using methods of quantum statistical physics we derive analytic expressions for…

Quantum Physics · Physics 2009-11-11 A. Kubasiak , J. Korbicz , J. Zakrzewski , M. Lewenstein

Calculating the abundance of thermally produced dark matter particles has become a standard procedure, with sophisticated methods guaranteeing a precision that matches the percent-level accuracy in the observational determination of the…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-12 Tobias Binder , Torsten Bringmann , Michael Gustafsson , Andrzej Hryczuk