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Related papers: Newtonian and relativistic polytropes

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The composition of neutron stars is an issue that has been studied for decades. Yet we do not know exactly what these very compact objects are made of. At this stage of the technological development the best we can do is to constrain the…

Solar and Stellar Astrophysics · Physics 2013-08-07 Marcio G B de Avellar , Jorge E Horvath

In this paper we study anisotropic spherical polytropes within the framework of general relativity. Using the anisotropic Tolman-Oppenheimer-Volkov (TOV) equations, we explore the relativistic anisotropic Lane-Emden equations. We find how…

General Relativity and Quantum Cosmology · Physics 2016-07-20 F. Shojai , M. Kohandel , A. Stepanian

The profile of a neutron star probes a very large range of densities, from the density of iron up to several times the density of saturated nuclear matter, and thus no theory of hadrons can be considered reliable if extended to those…

Nuclear Theory · Physics 2025-05-20 Francesca Sammarruca , Tomiwa Ajagbonna

The masses and radii of neutron stars are discussed in general relativity and scalar-tensor theory of gravity and the differences are compared with the current uncertainties stemming from the nuclear equation of state in the relativistic…

General Relativity and Quantum Cosmology · Physics 2019-07-16 F. J. Fattoyev

Neutron stars (NS) are compact objects with strong gravitational fields, and a matter composition subject to extreme physical conditions. The properties of strongly interacting matter at ultra-high densities and temperatures impose a big…

High Energy Astrophysical Phenomena · Physics 2022-10-19 R. V. Lobato , E. V. Chimanski , C. A. Bertulani

Neutron Stars (NSs) are compact stellar objects that are stable solutions in General Relativity. Their internal structure is usually described using an equation of state that involves the presence of ordinary matter and its interactions.…

High Energy Astrophysical Phenomena · Physics 2020-12-18 M. Ángeles Pérez-García , J. Silk

We review the current status and recent progress of microscopic many-body approaches and phenomenological models, which are employed to construct the equation of state of neutron stars. The equation of state is relevant for the description…

Nuclear Theory · Physics 2021-10-20 G. F. Burgio , I. Vidana , H. -J. Schulze , J. -B. Wei

We obtain bounds on the stability of various self-gravitating astrophysical objects using a new measure of shape complexity known as configurational entropy. We apply the method to Newtonian polytropes, neutron stars with an…

General Relativity and Quantum Cosmology · Physics 2016-07-06 Marcelo Gleiser , Nan Jiang

The equation of state of dense matter determines the structure of neutron stars, their typical radii, and maximum masses. Recent improvements in theoretical modeling of nuclear forces from the low-energy effective field theory of QCD has…

Nuclear Theory · Physics 2019-09-04 Jeremy W. Holt , Yeunhwan Lim

A general formula of the symmetry energy for many-body interaction is proposed and the commonly used two-body interaction symmetry energy is recovered. Within Landau's theory (Lt), we generalize two equations of state (EoS) CCS$\delta$3 and…

Nuclear Theory · Physics 2015-07-03 H. Zheng , J. Sahagun , A. Bonasera

Beyond black holes and neutron stars, new hypothetical compact objects have been proposed as potential astrophysical entities. In general, their properties have not yet been fully explored or understood, nor has it been proven whether or…

General Relativity and Quantum Cosmology · Physics 2024-06-10 Miguel Bezares , Nicolas Sanchis-Gual

In this lecture, we give a first introduction to neutron stars, based on fundamental physical principles. After outlining their amazing macroscopic properties, as obtained from observations, we infer the extreme conditions of matter in…

High Energy Astrophysical Phenomena · Physics 2010-01-11 Pierre M. Pizzochero

We obtain well behaved interior solutions describing hydrostatic equilibrium of anisotropic relativistic stars in scale-dependent gravity, where Newton's constant is allowed to vary with the radial coordinate throughout the star. Assuming…

General Relativity and Quantum Cosmology · Physics 2021-01-26 Grigoris Panotopoulos , Angel Rincon , Ilidio Lopes

Neutron stars are regarded as natural laboratories for the study of dense strong interaction matter. The equation of state (EoS) of dense matter computed in flat spacetime is used to predict the structure of neutron stars by solving the…

General Relativity and Quantum Cosmology · Physics 2022-10-27 Jianing Li , Tao Guo , Jiaxing Zhao , Lianyi He

We set up in detail the general formalism to model polytropic general relativistic stars with anisotropic pressure. We shall consider two different possible polytropic equations, all of which yield the same Lane-Emden equation in the…

General Relativity and Quantum Cosmology · Physics 2015-06-17 L. Herrera , W. Barreto

In this lecture, we give a first introduction to neutron stars, based on fundamental physical principles. After outlining their outstanding macroscopic properties, as obtained from observations, we infer the extreme conditions of matter in…

High Energy Astrophysical Phenomena · Physics 2016-09-27 Pierre M. Pizzochero

We present a physics-informed autoencoder designed to encode the equation of state of neutron stars into an interpretable latent space. In particular the input will be encoded in the mass, radius, and tidal deformability values of a neutron…

Computational Physics · Physics 2025-05-28 Francesco Di Clemente , Matteo Scialpi , Michał Bejger

The potential hadron-to-quark phase transition in neutron stars has not been fully understood as the property of cold, dense, and strongly interacting matter cannot be theoretically described by the first-principle perturbative…

Nuclear Theory · Physics 2025-05-01 Ronghao Li , Sophia Han , Zidu Lin , Lingxiao Wang , Kai Zhou , Shuzhe Shi

We explore constraints on the equation of state (EOS) of neutron-rich matter based on microscopic calculations up to nuclear densities and observations of neutron stars. In a previous work we showed that predictions based on modern nuclear…

High Energy Astrophysical Phenomena · Physics 2020-10-08 S. K. Greif , K. Hebeler , J. M. Lattimer , C. J. Pethick , A. Schwenk

One of the key ingredients to understand the properties of neutrons stars is the equation of state at finite densities far beyond nuclear saturation. Investigating the phase structure of quark matter that might be realized in the core of NS…

Nuclear Theory · Physics 2010-03-04 T. Klahn , C. D. Roberts , D. B. Blaschke , F. Sandin