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Related papers: Fermi gas and modified gravity

200 papers

The study of the dynamics of a two-body system in modified gravity constitutes a more complex problem than in Newtonian gravity. Numerical methods are typically needed to solve the equations of geodesics. Despite the complexity of the…

General Relativity and Quantum Cosmology · Physics 2018-11-13 Mariafelicia De Laurentis , Ivan De Martino , Ruth Lazkoz

In the free case, it is possible to define quantum fields which describe particles with integer or half-integer spin larger than one. It is shown that particles with integer spin must have Bose statistic and particles with half-integer-spin…

History and Philosophy of Physics · Physics 2017-04-04 Markus Fierz , Guglielmo Pasa

Nonequilibrium dynamics of an N-fold spin-degenerate ultracold Fermi gas is described in terms of beyond-mean-field Kadanoff-Baym equations for correlation functions. Using a nonperturbative expansion in powers of 1/N, the equations are…

Quantum Gases · Physics 2011-03-01 Matthias Kronenwett , Thomas Gasenzer

The quantum field theory of gravitation is constructed in terms of Lagrangian density of Dirac fields which couple to the electromagnetic field $A_\mu$ as well as the gravitational field $\cal G$. The gravity appears in the mass term as $…

General Physics · Physics 2008-04-17 Takehisa Fujita

It is shown that if a metric in quantum gravity can be decomposed as a sum of classical and quantum parts then Einstein quantum gravity looks approximately like modified gravity with a nonminimal interaction between gravity and matter.

General Relativity and Quantum Cosmology · Physics 2014-02-07 Vladimir Dzhunushaliev , Vladimir Folomeev , Burkhard Kleihaus , Jutta Kunz

This research is aimed at the revision of the thermodynamic concepts and their relationship with the General Relativity Theory (GRT) and how physical systems are affected when gravity is included in their thermodynamic description. We found…

General Relativity and Quantum Cosmology · Physics 2013-07-25 W. A. Rojas C. , R. Arenas S

Recently, Avik De and L.T. How claim that we have not followed an effective theory approach for $f(Q)$ gravity, missing relevant terms to compute the energy conditions [Phys. Rev. D 102, 024057 (2020)]. They also state that we did not…

General Relativity and Quantum Cosmology · Physics 2022-08-30 Sanjay Mandal , P. K. Sahoo , J. R. L. Santos

The thermodynamics of Dirac fields under the influence of external electromagnetic fields is studied. For perturbations which act only for finite time, the influence of the perturbation can be described by an automorphism which can be…

Mathematical Physics · Physics 2025-09-19 Romeo Brunetti , Klaus Fredenhagen , Nicola Pinamonti

Modifications of Einstein's theory of gravitation have been extensively considered in the past years, in connection to both cosmology and quantum gravity. Higher-curvature and higher-derivative gravity theories constitute the main examples…

General Relativity and Quantum Cosmology · Physics 2018-07-19 Alessio Belenchia , Marco Letizia , Stefano Liberati , Eolo Di Casola

While a wide variety of astrophysical and cosmological phenomena suggest the presence of Dark Matter, all evidence remains via its gravitational effect on the known matter. As such, it is conceivable that this evidence could be explained by…

General Relativity and Quantum Cosmology · Physics 2024-05-14 Ankit Kumar , Yen-Kheng Lim , P. Arumugam , Tom Zlosnik , Tomasz Paterek

We report on the measurement of the equation of state of a two-component Fermi gas of $^6$Li atoms with resonant interactions. By analyzing the \textit{in situ} density distributions of a population-imbalanced Fermi mixture reported in the…

Statistical Mechanics · Physics 2009-11-13 Yong-il Shin

General formulas are derived for the quasiparticle effective mass and the equation of state of the Fermi system with account of the interparticle attraction at long distances and repulsion at short distances. Calculations are carried out of…

Statistical Mechanics · Physics 2015-11-25 Yu. M. Poluektov , A. A. Soroka

Recent developments in observational cosmology have led to attempts to make modifications on both sides of the Einstein equation to explain some of the puzzling new findings. What follows is an examination of the source of gravity that we…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-23 Edward A Spiegel

We investigate dynamical properties of a one-component Fermi gas with dipole-dipole interaction between particles. Using a variational function based on the Thomas-Fermi density distribution in phase space representation, the total energy…

Other Condensed Matter · Physics 2011-04-12 T Sogo , L He , T Miyakawa , S Yi , H Lu , H Pu

It is believed that gravity will be explained in the framework of the existing quantum theory when one succeeds in eliminating divergencies at large momenta or small distances (although the phenomenon of gravity has been observed only at…

General Relativity and Quantum Cosmology · Physics 2008-07-28 Felix Lev

Recently, corrections of the $L(R)$ type to Einstein-Hilbert action that become important at small curvature are proposed. Those type of models intend to explain the observed cosmic acceleration without dark energy. We derive the full…

Astrophysics · Physics 2009-11-10 Xinhe Meng , Peng Wang

We generalize the $f(R)$ type gravity models by assuming that the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar $R$ and of the matter Lagrangian $L_m$. We obtain the gravitational field equations in the…

General Relativity and Quantum Cosmology · Physics 2011-02-09 Tiberiu Harko , Francisco S. N. Lobo

We point out an important hidden inconsistency in Fermi's probability of the quantum states that engendered inconsistent/inaccurate equations-of-state extensively used in the literature to model nonideal plasma systems. The importance of…

Plasma Physics · Physics 2015-05-30 Mofreh R. Zaghloul

In this chapter, we describe three related studies of the universal physics of two-component unitary Fermi gases with resonant short-ranged interactions. First we discuss an ab initio auxiliary field quantum Monte Carlo technique for…

Quantum Gases · Physics 2012-03-21 Aurel Bulgac , Michael McNeil Forbes , Piotr Magierski

According to maximum entropy principle, it has been proved that the gravitational field equations could be derived by the extrema of total entropy for perfect fluid, which implies that thermodynamic relations contain information of gravity.…

General Relativity and Quantum Cosmology · Physics 2018-01-17 Xiongjun Fang , Xiaokai He , Jiliang Jing