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Related papers: Neutron stars and the cosmological constant proble…

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We study the QCD phase diagram using a non-local SU(3) NJL model with vector interactions among quarks. We analyze several thermodynamic quantities such as entropy and specific heat, and study the influence of vector interactions on the…

High Energy Astrophysical Phenomena · Physics 2017-09-06 German Malfatti , G. A. Contrera , M. Orsaria , F. Weber

Finite density corrections to the lighter-than-QCD axion can invert the effective axion potential, sourcing a non-trivial axion field inside dense objects. We perform the first numerical study of the complete dynamics of the…

High Energy Physics - Phenomenology · Physics 2025-11-19 Yonatan Kahn , Michael Wentzel , Nicolás Yunes

The transition from hadronic matter to quark matter in the core of neutron stars is likely to be associated with the appearance of a mixed phase, leading to a smooth variation of the star density profile. We discuss the results of a…

Astrophysics · Physics 2009-11-10 Omar Benhar , Roberto Rubino

The cosmological constant term (CC), $\Lambda$, is a pivotal ingredient in the standard model of cosmology or $\Lambda$CDM, but it is a rigid quantity for the entire cosmic history. This is unnatural and inconsistent. Different theoretical…

High Energy Physics - Theory · Physics 2024-11-12 Joan Solà Peracaula , Cristian Moreno-Pulido

There are now two cosmological constant problems: (i) why the vacuum energy is so small and (ii) why it comes to dominate at about the epoch of galaxy formation. Anthropic selection appears to be the only approach that can naturally resolve…

High Energy Physics - Theory · Physics 2007-06-20 Alexander Vilenkin

We study the structural and dynamical consequences of introducing a distributional density profile inside a neutron star, representing a massless, topological shell located at an arbitrary radius. We incorporate this effect into the…

General Relativity and Quantum Cosmology · Physics 2026-04-15 Debojoti Kuzur , Kamal Krishna Nath

In this letter we calculate the energy loss of highly magnetized neutron star due to friction with quantum vacuum, namely Quantum Vacuum Friction (QVF). Taking into account one-loop corrections in the effective Heisenberg-Euler Lagrangian…

Astrophysics · Physics 2009-06-23 Arnaud Dupays , Carlo Rizzo , Dimitar Bakalov , Giovanni F. Bignami

In this work we study the case of deconfinement in compact star interiors in the presence of a strong first order phase transition associated to a critical end point in the QCD phase diagram. Neutron stars fulfilling these conditions show a…

High Energy Astrophysical Phenomena · Physics 2016-09-14 D. E. Alvarez-Castillo

Anisotropic phases potentially play a role in the internal composition of neutron stars, the main laboratory for the phase structure of QCD at high baryon densities. We review the study of such a phase, the chiral density wave, within a…

Nuclear Theory · Physics 2025-11-07 Orestis Papadopoulos , Andreas Schmitt

Numerical simulations of binary neutron stars by Wilson, Mathews, and Marronetti indicated that neutron stars that are stable in isolation can be made to collapse to black holes when placed in a binary. This claim was surprising as it ran…

Astrophysics · Physics 2009-11-13 Marc Favata

Astrophysical observations of neutron stars probe the structure of dense nuclear matter and have the potential to reveal phase transitions at high densities. Most recent analyses are based on parametrized models of the equation of state…

High Energy Astrophysical Phenomena · Physics 2025-05-13 Reed Essick , Isaac Legred , Katerina Chatziioannou , Sophia Han , Philippe Landry

In this conference-proceedings contribution, we review recent advances in placing model-independent constraints on the properties of cold and dense QCD matter inside neutron stars. In addition to introducing new bounds for the Equation of…

High Energy Astrophysical Phenomena · Physics 2019-04-03 Eemeli Annala , Tyler Gorda , Aleksi Kurkela , Joonas Nättilä , Aleksi Vuorinen

We study the effect of a strong magnetic field on the properties of neutron stars with a quark-hadron phase transition. It is shown that the magnetic field prevents the appearance of a quark phase, enhances the leptonic fraction, decreases…

Nuclear Theory · Physics 2014-11-20 A. Rabhi , H. Pais , P. K. Panda , C. Providencia

I argue that a solution to the cosmological constant problem is to assume that the expectation value of the quantum vacuum stress-energy tensor is proportional to the metric tensor with a negative energy density and positive pressure. This…

General Physics · Physics 2018-05-09 Emilio Santos

In a cosmological phase transition in theories that admit Q-balls there is a value of the soliton charge above which the soliton becomes unstable and expands, converting space to the true vacuum, much like a critical bubble in the case of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Dimitrios Metaxas

We study the role of the pasta phases on the properties of rotating and magnetized neutron stars. In order to investigate such systems, we make use of two different relativistic mean-field unified inner-crust--core equations of state, with…

Nuclear Theory · Physics 2020-09-23 Ivo Sengo , Helena Pais , Bruno Franzon , Constança Providência

Neutron stars are extremely relativistic objects which abound in our universe and yet are poorly understood, due to the high uncertainty on how matter behaves in the extreme conditions which prevail in the stellar core. It has recently been…

General Relativity and Quantum Cosmology · Physics 2013-07-30 Andrea Maselli , Vitor Cardoso , Valeria Ferrari , Leonardo Gualtieri , Paolo Pani

The old cosmological constant problem is to understand why the vacuum energy is so small; the new problem is to understand why it is comparable to the present mass density. Several approaches to these problems are reviewed. Quintessence…

Astrophysics · Physics 2007-05-23 Steven Weinberg

Transitions of nuclear compositions in the crust of a neutron star induced by stellar spin-down are evaluated at zero temperature. We construct a compressible liquid-drop model for the energy of nuclei immersed in a neutron gas, including…

Astrophysics · Physics 2016-08-30 Kei Iida , Katsuhiko Sato

The different phases of QCD at finite temperature and density lead to interesting effects in cosmology and astrophysics. In this work I review some aspects of the cosmological QCD transition and of astrophysics at high baryon density.

High Energy Physics - Phenomenology · Physics 2009-10-31 Dominik J. Schwarz