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Related papers: Negative temperature for negative lapse function

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We study the thermal behavior of the negative dimensional harmonic oscillator of Dunne and Halliday that at zero temperature, due to a hidden BRST symmetry of the classical harmonic oscillator, is shown to be equivalent to the Grassmann…

High Energy Physics - Theory · Physics 2009-10-22 Silvio J. Rabello , Arvind N. Vaidya , Luiz Claudio M. de Albuquerque

The phenomenon of the so called Fermion condensation, a phase transition analogous to Bose condensation but for Fermions, postulated in the past to occur in systems with strong momentum dependent forces, is reanalysed in a model with…

Condensed Matter · Physics 2009-10-28 J. Dukelsky , V. A. Khodel , P. Schuck , V. R. Shaginyan

This pedagogical comment highlights three misconceptions concerning the usefulness of the concept of negative temperature; being derived from the usual, often termed Boltzmann, definition of entropy. First, both the Boltzmann and Gibbs…

Statistical Mechanics · Physics 2016-04-06 Julian Poulter

We consider a gas of fermions with non-zero spin at temperature $T$ and chemical potential $\mu$. We show that if the range of the interparticle interaction is small compared to the mean particle distance, the thermodynamic pressure differs…

Mathematical Physics · Physics 2015-06-26 Robert Seiringer

We investigate the relationship between ground-state (zero-temperature) quantum phase transitions in systems with variable Hamiltonian parameters and classical (temperature-driven) phase transitions in standard thermodynamics. An analogy is…

Nuclear Theory · Physics 2009-11-11 Pavel Cejnar , Stefan Heinze , Jan Dobes

A simple and computationally efficient algorithm enables implementing negative temperature values in a spin dynamics simulation. The algorithm uses a Langevin spin dynamics thermostat with a negative damping parameter, enabling the…

Materials Science · Physics 2024-03-05 Pui-Wai Ma , Sergei L. Dudarev

We analyze entanglement generated by the Schwinger effect using a mode-by-mode formalism for scalar and spinor QED in constant backgrounds. Starting from thermal initial states, we derive compact, closed-form results for bipartite…

High Energy Physics - Theory · Physics 2026-02-13 Dimitrios Kranas , Amaury Marchon , Silvia Pla

We describe an extension of the Keldysh method for fermions from constant temperature to steady state case with spatially varying temperature field.This is done with the use on the imaginary section of the Keldysh path of a thermal…

High Energy Physics - Theory · Physics 2020-03-24 Alyx Jourjine

Tolman's relation for the temperature gradient in an equilibrium self-gravitating general relativistic fluid is broadly accepted within the general relativity community. However, the concept of temperature gradients in thermal equilibrium…

General Relativity and Quantum Cosmology · Physics 2019-03-01 Jessica Santiago , Matt Visser

The notion of negative absolute temperature emerges naturally from Boltzmann's definition of "surface" microcanonical entropy in isolated systems with a bounded energy density. Recently, the well-posedness of such construct has been…

Statistical Mechanics · Physics 2017-05-31 Pierfrancesco Buonsante , Roberto Franzosi , Augusto Smerzi

We investigate the thermodynamics of non-relativistic and relativistic ideal gases on the spacetime with noncommutative fuzzy geometry. We first find that the heat capacities of the non-relativistic ideal boson and fermion on the fuzzy…

High Energy Physics - Theory · Physics 2009-09-28 Wung-Hong Huang

The controversial existence of negative temperatures has stirred interesting debates that have reached the foundations of thermodynamics, including questions on the second law, the Carnot efficiency and the statistical definition of…

Statistical Mechanics · Physics 2019-06-26 Salvatore Calabrese , Amilcare Porporato

After negative temperature is restated, we find that it will derive necessarily decrease of entropy. Negative temperature is based on the Kelvin scale and the condition dU>0 and dS<0. Conversely, there is also negative temperature for dU<0…

General Physics · Physics 2007-05-23 Yi-Fang Chang

In this paper we calculate the basic thermodynamical quantities for a system of bosonic simple harmonic oscillators (BSHOs) and the corresponding system of fermionic simple harmonic oscillators (FSHOs) using a dispersion relationship…

Statistical Mechanics · Physics 2020-01-08 Metin Güner , Metin Arık

Dynamical properties of a generic null surface are known to have a thermodynamic interpretation. Such an interpretation is completely based on an analogy between the usual law of thermodynamics and structure of gravitational field equation…

General Relativity and Quantum Cosmology · Physics 2022-01-12 Surojit Dalui , Bibhas Ranjan Majhi , T. Padmanabhan

String theories naturally predict a negative, while observations on the exponential expansion of the present Universe require a positive value for the cosmological constant. Solution to resolve this discrepancy is known in the framework of…

General Relativity and Quantum Cosmology · Physics 2026-04-02 E. N. Nyergesy , I. G. Márián , A. Trombettoni , I. Nándori

Thermal duality is a relationship between the behaviour of heterotic string models of the $E(8)x E(8)$ or $SO(32)$ types at inversely related temperatures, a variant of T duality in the Euclidean regime. This duality would have consequences…

High Energy Physics - Theory · Physics 2015-09-17 Michael Hewitt

In this work, we study some thermodynamical aspects associated with torsion in a flat FLRW spacetime cosmic evolution. By implementing two Ansatze for the torsion term, we find that the model admits a phantom regime or a quintessence…

General Relativity and Quantum Cosmology · Physics 2020-06-26 Miguel Cruz , Fernando Izaurieta , Samuel Lepe

Thermal fluctuations tend to destroy long-range phase correlations. Consequently, bosons in a lattice will undergo a transition from a phase-coherent superfluid as the temperature rises. Contrary to common intuition, however, we show that…

Quantum Gases · Physics 2015-03-17 Andrew Robertson , Victor M. Galitski , Gil Refael

For the free Fermion gas at thermodynamic equilibrium, the temperature which represents the averaged kinetic energy is demonstrated to have the proper property which is invariant under the Lorentz boost, using the conceptions of the…

Classical Physics · Physics 2007-05-23 W. Z. Jiang