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Related papers: Neutron Stars in Aether Scalar-Tensor Theory

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In this work, we systematically derive the Einstein field equations in general relativity and $f(\mathcal{R})$ gravity, the Tolman-Oppenheimer-Volkoff (TOV) equation, and the expressions for axial and polar Tidal Love Numbers (TLNs) for…

General Relativity and Quantum Cosmology · Physics 2023-06-14 Pinaki Roy , Bharat Kumar

We derive a Tolman-Oppenheimer-Volkoff equation in neutron star systems within the modified $f(T, \mathcal{T})$-gravity class of models using a perturbative approach. In our approach $f(T, \mathcal{T})$-gravity is considered to be a static…

General Relativity and Quantum Cosmology · Physics 2017-05-08 Mark Pace , Jackson Levi Said

The potential role of a cosmic vacuum dark component in the properties of neutron stars is investigated. It is assumed that the static, spherically symmetric distribution of matter within neutron stars is supported by two distinct…

High Energy Physics - Phenomenology · Physics 2024-08-05 L. F. Araujo , J. A. S. Lima , G. Lugones

The presence of dark matter has been ascertained through a wealth of astrophysical and cosmological phenomena and its nature is a central puzzle in modern science. Elementary particles stand as the most compelling explanation. They have…

High Energy Physics - Phenomenology · Physics 2019-10-02 Daniel A. Camargo , Farinaldo S. Queiroz , Riccardo Sturani

Tensor-scalar theory is a wide class of alternative theory of gravitation that can be motivated by higher dimensional theories, by models of dark matter or dark ernergy. In the general case, the scalar field will couple non-universally to…

General Relativity and Quantum Cosmology · Physics 2019-05-22 A. Hees , O. Minazzoli , E. Savalle , Y. V. Stadnik , P. Wolf , B. Roberts

We generalize tensor-scalar theories of gravitation by the introduction of an abnormally weighting type of energy. This theory of tensor-scalar anomalous gravity is based on a relaxation of the weak equivalence principle that is now…

Astrophysics · Physics 2009-01-14 J. -M. Alimi , A. Füzfa

Neutron stars with the isovector scalar $\delta$-field are studied in the framework of the relativistic mean field ($RMF$) approach in a pure nucleon plus lepton scheme. The $\delta$-field leads to a larger repulsion in dense neutron-rich…

Nuclear Theory · Physics 2009-11-10 B. Liu , H. Guo , M. Di Toro , V. Greco

The understanding of stellar structure represents the crossroads of our theories of the nuclear force and the gravitational interaction under the most extreme conditions observably accessible. It provides a powerful probe of the strong…

General Relativity and Quantum Cosmology · Physics 2020-09-15 Gonzalo J. Olmo , Diego Rubiera-Garcia , Aneta Wojnar

The discovery of cosmic acceleration has presented a unique challenge for cosmologists. As observational cosmology forges ahead, theorists have struggled to make sense of a standard model that requires extreme fine tuning. This challenge is…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-02 Chanda Prescod-Weinstein , Niayesh Afshordi , Michael L. Balogh

We continue to study the spherically symmetric vacuum solutions of the tensor-four-scalars theory which is a modification of general relativity. Our aim is to construct vacuum solutions with asymptotically constant circular velocity curves…

Astrophysics of Galaxies · Physics 2012-06-11 Günter Scharf , Fabrice Larere

Recently proposed theories based on the cosmic presence of a vectorial field are compared and contrasted. In particular the so called Einstein aether theory is discussed in parallel with a recent proposal of a strained space-time theory…

General Relativity and Quantum Cosmology · Physics 2008-11-26 A. Tartaglia , N. Radicella

We develop a theory of dark matter based on a previously proposed picture, in which a complex vacuum scalar field makes the universe a superfluid, with the energy density of the superfluid giving rise to dark energy, and variations from…

General Relativity and Quantum Cosmology · Physics 2014-04-30 Kerson Huang , Chi Xiong , Xiaofei Zhao

Scalar-Tensor-Vector Gravity (STVG), also referred as MOdified Gravity (MOG), is an alternative theory of the gravitational interaction. Its weak field approximation has been successfully used to described Solar System observations, galaxy…

General Relativity and Quantum Cosmology · Physics 2017-02-02 Federico G. Lopez Armengol , Gustavo E. Romero

Neutron stars are the most dense objects in the observable Universe and conventionally one uses nuclear theory to obtain the equation of state (EOS) of dense hadronic matter and the global properties of these stars. In this work, we review…

Nuclear Theory · Physics 2009-02-03 T. K. Jha

The so-called Einstein-Aether theory is General Relativity coupled (at second derivative order) to a dynamical unit time-like vector field (the aether). It is a Lorentz-violating theory, and gained much attention in the recent years. In the…

General Relativity and Quantum Cosmology · Physics 2014-04-16 Hao Wei , Xiao-Peng Yan , Ya-Nan Zhou

I describe a tensor-vector-scalar theory that reconciles the galaxy scale success of modified Newtonian dynamics (MOND) with the cosmological scale evidence for CDM. The theory provides a cosmological basis for MOND in the sense that the…

Astrophysics · Physics 2009-11-10 R. H. Sanders

Binary pulsar observations and gravitational wave detections seriously constrained scalar-tensor theories with massless scalar field allowing only small deviations from general relativity. If we consider a nonzero mass of the scalar field,…

General Relativity and Quantum Cosmology · Physics 2018-08-15 Kalin V. Staykov , Dimitar Popchev , Daniela D. Doneva , Stoytcho S. Yazadjiev

The past years have witnessed tremendous progress in understanding the properties of neutron stars and of the dense matter in their cores, made possible by electromagnetic observations of neutron stars and the detection of gravitational…

The Noether symmetry analysis is applied in a multi-scalar field cosmological model in teleparallel gravity. In particular, we consider two scalar fields with interaction in scalar-torsion theory. The field equations have a minisuperspace…

General Relativity and Quantum Cosmology · Physics 2023-04-05 Konstantinos F. Dialektopoulos , Genly Leon , Andronikos Paliathanasis

We study the cosmological evolution of the field equations in the context of Einstein-Aether cosmology by including a scalar field in a spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker spacetime. Our analysis is separated into two…

General Relativity and Quantum Cosmology · Physics 2020-01-17 Andronikos Paliathanasis , G. Papagiannopoulos , Spyros Basilakos , John D. Barrow