4.7 Article

Cooling process of substellar objects in scalar-tensor gravity

Related references

Note: Only part of the references are listed.
Article Physics, Particles & Fields

Early evolution of fully convective stars in scalar-tensor gravity

Debora Aguiar Gomes et al.

Summary: In this work, the early evolution of low-mass fully convective stars is studied in the context of DHOST theories of gravity, specifically focusing on the modifications to the hydrostatic equilibrium equation and their effects on different evolutionary phases. The Hayashi tracks are found to be shifted and the star's age is significantly modified under the influence of the theory's parameter.

EUROPEAN PHYSICAL JOURNAL C (2023)

Article Astronomy & Astrophysics

Fermi gas and modified gravity

Aneta Wojnar

Summary: The equations of state for Fermi gas in modified gravity are derived by maximizing the Fermi-Dirac entropy in both relativistic and nonrelativistic cases. It is shown that the microphysics of a physical system at a statistical state must depend on a specific theory of gravity in order to be consistently described.

PHYSICAL REVIEW D (2023)

Article Astronomy & Astrophysics

Metric-affine effects in crystallization processes of white dwarfs

Surajit Kalita et al.

Summary: We analyze the effects of modified gravity on specific heats, Debye temperature, crystallization process, and cooling mechanism in white dwarfs. We derive the Lane-Emden-Chandra-sekhar equation and relate it to the cooling process equations for Palatini f(R) gravity. Moreover, for the first time in the literature, we show that the gravity model plays a crucial role not only in the mass and size of the white dwarf but also affects their internal properties. We further demonstrate that modified gravity can decrease the cooling age significantly.

PHYSICAL REVIEW D (2023)

Article Astronomy & Astrophysics

Interiors of Terrestrial Planets in Metric-Affine Gravity

Aleksander Kozak et al.

Summary: Using a semiempirical approach, this study demonstrates that modified gravity has an impact on the internal properties of terrestrial planets, including their core, mantle, and core-mantle boundary. These findings are also applied to modeling a two-layer exoplanet under Palatini f(R) gravity.

UNIVERSE (2022)

Article Astronomy & Astrophysics

Testing Screened Modified Gravity

Philippe Brax et al.

Summary: This article discusses the violation of known bounds on gravitation by long range scalar fields with a coupling to matter, and how this is evaded through screening mechanisms. It further explores how these mechanisms will be tested at different scales in laboratory and astrophysical and cosmological contexts.

UNIVERSE (2022)

Article Physics, Mathematical

Non-homogeneous exoplanets in metric-affine gravity

Aleksander Kozak et al.

Summary: This article provides an improved description of the planets' interior and examines the effects of modified gravity on Earth-like planets composed of iron core and silicate mantle.

INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS (2022)

Article Astronomy & Astrophysics

Weak-field limit of f (R) gravity to unify peculiar white dwarfs

Surajit Kalita et al.

Summary: In recent years, there has been a growing interest in studying the sub- and super-Chandrasekhar limiting mass white dwarfs, which are potential candidates to produce different types of supernovae. Modifying Einstein's gravity theory with f(R) gravity seems to be one of the best choices to explain these peculiar white dwarfs. This paper derives the weak-field limit of f(R) gravity and uses it to study the structures of sub- and super-Chandrasekhar limiting mass white dwarfs.

PHYSICS LETTERS B (2022)

Article Multidisciplinary Sciences

Gaia, Fundamental Physics, and Dark Matter

Michael Perryman et al.

Summary: The Gaia space astrometry mission is providing important data for fundamental physics research and contributing to our understanding of dark matter. The study suggests that deep and surprising insights can be obtained from this data set. The researchers propose searching for a connection between stellar activity, dark matter streams, and planetary configuration in nearby exoplanetary systems.

SYMMETRY-BASEL (2022)

Article Astronomy & Astrophysics

Searching for dark energy with the Sun

Ippocratis D. Saltas et al.

Summary: This article discusses general extensions of general relativity that predict a fifth force, which can be tested through precision tests on the solar equilibrium structure. The authors explain how different regions of the Sun can be used to test gravity and demonstrate that the fifth force leaves a signature on the solar sound speed. They also place constraints on the strength of the fifth-force coupling based on observational errors. The findings have significant implications for understanding the nature of gravity and can be applied to theories beyond general relativity.

ASTRONOMY & ASTROPHYSICS (2022)

Article Astronomy & Astrophysics

Giant planet formation in Palatini gravity

Aneta Wojnar

Summary: The study focuses on the critical core mass and the conditions for a planet to possess a massive gaseous envelope around a solid core during early planetary formation.

PHYSICAL REVIEW D (2022)

Article Physics, Particles & Fields

Pre-main sequence evolution of low-mass stars in Eddington-inspired Born-Infeld gravity

Merce Guerrero et al.

Summary: This study investigates three aspects of the early-evolutionary phases in low-mass stars within Eddington-inspired Born-Infeld (EiBI) gravity, including the Hayashi tracks, the minimum mass required for the main sequence, and the maximum mass for a fully convective star. The results show a dependence of these quantities on both the EiBI parameter and the star's central density.

EUROPEAN PHYSICAL JOURNAL C (2022)

Article Astronomy & Astrophysics

Axion instability supernovae

Jeremy Sakstein et al.

Summary: This study investigates the equilibrium of new particles coupled to the Standard Model in stellar cores and their astrophysical consequences for massive stars. Specifically focusing on axions in the cosmological triangle, it finds that axion production can drive a new stellar instability leading to explosive nuclear burning or star disruption. The study predicts a shift in the upper black hole mass gap and suggests that axion-instability supernovae are more common and observable targets for the James Webb Space Telescope.

PHYSICAL REVIEW D (2022)

Article Astronomy & Astrophysics

Stability criterion for white dwarfs in Palatini f(R) gravity

Lupamudra Sarmah et al.

Summary: Recent observations suggest the violation of Chandrasekhar mass limit in supernovae and the existence of white dwarfs with super- and sub-Chandrasekhar limiting masses. In this study, we investigate these objects using Palatini f(R) gravity in the context of general relativistic extensions. We determine the limiting masses and dynamical instability criteria for white dwarfs in this gravitational theory. Furthermore, we demonstrate that the conventional positivity condition remains valid for stability in Palatini gravity.

PHYSICAL REVIEW D (2022)

Article Physics, Mathematical

White dwarf stars in modified gravity

Aneta Wojnar

Summary: Modified gravity framework may provide alternative explanations to white dwarfs' cooling processes, age determination, and Chandrasekhar mass limits. Additionally, the Chandrasekhar limit has been obtained from Palatini f(Script capital R) gravity introduced by a simple Lane-Emden model.

INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS (2021)

Article Astronomy & Astrophysics

Equation of states in the curved spacetime of spherical degenerate stars

Golam Mortuza Hossain et al.

Summary: In the study of spherical degenerate stars, effects of general relativity and gravitational time dilation are crucial and ignoring them can lead to significantly underestimating the mass limits of these compact stars.

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS (2021)

Article Astronomy & Astrophysics

White dwarfs and generalized uncertainty principle

I. H. Belfaqih et al.

Summary: This study investigates white dwarfs' mass and radius with three generalized uncertainty principle (GUP) models, finding that the quadratic GUP model is favored over the linear model. It is possible to obtain a higher mass limit in certain scenarios, and the linear-quadratic GUP model may allow for the formation of more massive stable white dwarfs.

INTERNATIONAL JOURNAL OF MODERN PHYSICS D (2021)

Article Astronomy & Astrophysics

Modified gravity in the interior of population II stars

Shaswata Chowdhury et al.

Summary: The study investigates the effects of modified gravity beyond Horndeski theory in the interior of a population II star, finding that reduced gravity may result in decreased luminosity and increased radius of the star, but some effects are reversed near the core. The model provides a constraint on the modified gravity parameter within its limitations.

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS (2021)

Article Physics, Multidisciplinary

Exoplanets as Sub-GeV Dark Matter Detectors

Rebecca K. Leane et al.

Summary: Exoplanets are presented as new targets for discovering dark matter. Through estimating the sensitivity of upcoming infrared telescopes, actionable searches for discovering or excluding dark matter are found. Dark matter with masses above about an MeV can be probed with exoplanets, with scattering cross sections stronger than existing limits.

PHYSICAL REVIEW LETTERS (2021)

Article Astronomy & Astrophysics

A New Equation of State for Dense Hydrogen-Helium Mixtures. II. Taking into Account Hydrogen-Helium Interactions

Gilles Chabrier et al.

Summary: In a recent paper, a new equation of state (EOS) for dense hydrogen/helium mixtures covering the temperature-density domain from solar-type stars to brown dwarfs and gaseous planets was derived. This EOS goes beyond previous calculations by including H/He interactions, which lead to phase separation at low temperature and high density conditions. The tables of this new EOS are publicly available.

ASTROPHYSICAL JOURNAL (2021)

Article Physics, Particles & Fields

Invariant quantities of scalar-tensor theories for stellar structure

Aleksander Kozak et al.

Summary: The translation introduces relativistic hydrostatic equilibrium equations for a wide class of gravitational theories possessing a scalar-tensor representation, showing that the stellar structure equations can be written with respect to the scalar-tensor invariants. This allows for interpreting their physical role.

EUROPEAN PHYSICAL JOURNAL C (2021)

Article Astronomy & Astrophysics

Higher mass limits of neutron stars from the equation of states in curved spacetime

Golam Mortuza Hossain et al.

Summary: The equations of state for neutron stars should take into account the effect of gravitational time dilation, resulting in a higher mass limit due to the varying interior metric over the length scale of the star.

PHYSICAL REVIEW D (2021)

Article Astronomy & Astrophysics

Jupiter and jovian exoplanets in Palatini f ((R)over-bar) gravity

Aneta Wojnar

Summary: Palatini f((R) over bar) gravity has been shown to impact certain parts of substellar evolution, such as fragmentation of a gaseous cloud and cooling of Jupiter-like planets. Simple models describing these processes demonstrate differences in opacity mass limit and cooling time of jovian planets in modified gravity.

PHYSICAL REVIEW D (2021)

Article Astronomy & Astrophysics

Metric-affine gravity effects on terrestrial exoplanet profiles

Aleksander Kozak et al.

Summary: The mass-radius relations of homogeneous cold spheres made from six common solid materials found in terrestrial planets are discussed, along with an additional degeneracy in (exo)planet profiles and their properties derived from findings in Palatini f(R) gravity framework. Furthermore, a new test of gravity is proposed where seismic data from earthquakes and marsquakes can be used to test and constrain gravity models.

PHYSICAL REVIEW D (2021)

Article Astronomy & Astrophysics

Direct detection of dark energy: The XENON1T excess and future prospects

Sunny Vagnozzi et al.

Summary: This study explores the potential for direct detection of dark energy through terrestrial dark matter direct detection experiments. The research suggests that dark energy quanta could be produced in the Sun, interacting with Standard Model particles on Earth, presenting the possibility of testing dark energy. Screening mechanisms prevent the production of dark energy in stellar cores, allowing for detectable signals on Earth and potentially achieving the first direct detection of dark energy. Future detectors such as XENONnT, PandaX-4T, and LUX-ZEPLIN may help confirm this scenario.

PHYSICAL REVIEW D (2021)

Article Astronomy & Astrophysics

Parameterized nonrelativistic limit of stellar structure equations in Ricci-based gravity theories

Gonzalo J. Olmo et al.

Summary: This study presents the nonrelativistic limit of the stellar structure equations of Ricci-based gravities, characterized by four parameters, and discusses its relevance for the phenomenology of nonrelativistic stars.

PHYSICAL REVIEW D (2021)

Article Astronomy & Astrophysics

Cooling process of brown dwarfs in Palatini f(R) gravity

Maria Benito et al.

Summary: The study presents an analytical model for the evolution of brown dwarfs in quadratic Palatini f(R) gravity, improving on previous studies by incorporating a more realistic description of the partially degenerate state and considering the hydrogen metallic-molecular phase transition. The revised cooling process for substellar objects is also addressed in this improved model.

PHYSICAL REVIEW D (2021)

Article Astronomy & Astrophysics

Lithium abundance is a gravitational model dependent quantity

Aneta Wojnar

Summary: The dependence of lithium abundance on modified gravity in low-mass stellar objects introduces potential uncertainties to age determination techniques if they rely on the light element depletion method.

PHYSICAL REVIEW D (2021)

Review Astronomy & Astrophysics

Jupiter's Interior as Revealed by Juno

David J. Stevenson

ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES, VOL 48, 2020 (2020)

Review Physics, Multidisciplinary

Stellar structure models in modified theories of gravity: Lessons and challenges

Gonzalo J. Olmo et al.

PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS (2020)

Article Astronomy & Astrophysics

Early evolutionary tracks of low-mass stellar objects in modified gravity

Aneta Wojnar

PHYSICAL REVIEW D (2020)

Article Astronomy & Astrophysics

Modified gravity and the black hole mass gap

Maria C. Straight et al.

PHYSICAL REVIEW D (2020)

Article Astronomy & Astrophysics

Mimetic gravity as DHOST theories

David Langlois et al.

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS (2019)

Review Physics, Multidisciplinary

Horndeski theory and beyond: a review

Tsutomu Kobayashi

REPORTS ON PROGRESS IN PHYSICS (2019)

Article Physics, Multidisciplinary

Obtaining Precision Constraints on Modified Gravity with Helioseismology

Ippocratis D. Saltas et al.

PHYSICAL REVIEW LETTERS (2019)

Article Astronomy & Astrophysics

Understanding Jupiter's deep interior: the effect of a dilute core

Dongdong Ni

ASTRONOMY & ASTROPHYSICS (2019)

Article Physics, Particles & Fields

The fractional angular momentum realized by a neutral cold atom

Jian Jing et al.

EUROPEAN PHYSICAL JOURNAL C (2019)

Article Physics, Particles & Fields

Brown dwarfs in Eddington-inspired Born-Infeld and beyond Horndeski theories

A. S. Rosyadi et al.

EUROPEAN PHYSICAL JOURNAL C (2019)

Article Astronomy & Astrophysics

A New Equation of State for Dense Hydrogen-Helium Mixtures

G. Chabrier et al.

ASTROPHYSICAL JOURNAL (2019)

Article Astronomy & Astrophysics

Minimum main sequence mass in quadratic Palatini f(R) gravity

Gonzalo J. Olmo et al.

PHYSICAL REVIEW D (2019)

Article Astronomy & Astrophysics

Vainshtein regime in scalar-tensor gravity: Constraints on degenerate higher-order scalar-tensor theories

Marco Crisostomi et al.

PHYSICAL REVIEW D (2019)

Article Astronomy & Astrophysics

White dwarfs and revelations

Ippocratis D. Saltas et al.

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS (2018)

Article Astronomy & Astrophysics

Observable traces of non-metricity: New constraints on metric-affine gravity

Adria Delhom-Latorre et al.

PHYSICS LETTERS B (2018)

Article Astronomy & Astrophysics

Constraints on modified gravity models from white dwarfs

Srimanta Banerjee et al.

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS (2017)

Article Astronomy & Astrophysics

Deceleration versus acceleration universe in different frames of F(R) gravity

Sebastian Bahamonde et al.

PHYSICS LETTERS B (2017)

Review Physics, Multidisciplinary

Modified gravity theories on a nutshell: Inflation, bounce and late-time evolution

S. Nojiri et al.

PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS (2017)

Review Astronomy & Astrophysics

The Juno Mission

S. J. Bolton et al.

SPACE SCIENCE REVIEWS (2017)

Article Astronomy & Astrophysics

The Fuzziness of Giant Planets' Cores

Ravit Helled et al.

ASTROPHYSICAL JOURNAL LETTERS (2017)

Article Astronomy & Astrophysics

Jupiter internal structure: the effect of different equations of state

Y. Miguel et al.

ASTRONOMY & ASTROPHYSICS (2016)

Article Physics, Particles & Fields

Extending the Higgs sector: an extra singlet

S. I. Godunov et al.

EUROPEAN PHYSICAL JOURNAL C (2016)

Article Astronomy & Astrophysics

Hamiltonian analysis of higher derivative scalar-tensor theories

David Langlois et al.

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS (2016)

Article Physics, Multidisciplinary

White Dwarf Critical Tests for Modified Gravity

Rajeev Kumar Jain et al.

PHYSICAL REVIEW LETTERS (2016)

Review Astronomy & Astrophysics

Analytic Models of Brown Dwarfs and the Substellar Mass Limit

Sayantan Auddy et al.

ADVANCES IN ASTRONOMY (2016)

Article Astronomy & Astrophysics

Jupiter internal structure: the effect of different equations of state

Y. Miguel et al.

ASTRONOMY & ASTROPHYSICS (2016)

Review Geochemistry & Geophysics

Understanding Jupiter's interior

Burkhard Militzer et al.

JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS (2016)

Article Astronomy & Astrophysics

Modified gravity inside astrophysical bodies

Ryo Saito et al.

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS (2015)

Article Astronomy & Astrophysics

Testing gravity using dwarf stars

Jeremy Sakstein

PHYSICAL REVIEW D (2015)

Article Astronomy & Astrophysics

Invariant quantities in the scalar-tensor theories of gravitation

Laur Jaerv et al.

PHYSICAL REVIEW D (2015)

Article Astronomy & Astrophysics

Astrophysical probes of the Vainshtein mechanism: Stars and galaxies

Kazuya Koyama et al.

PHYSICAL REVIEW D (2015)

Article Physics, Multidisciplinary

Hydrogen Burning in Low Mass Stars Constrains Scalar-Tensor Theories of Gravity

Jeremy Sakstein

PHYSICAL REVIEW LETTERS (2015)

Article Astronomy & Astrophysics

Physics at the surface of a star in Eddington-inspired Born-Infeld Gravity

Hyeong-Chan Kim

PHYSICAL REVIEW D (2014)

Article Astronomy & Astrophysics

Analytical model for the evolution of giant extrasolar planets

J. R. Donnison et al.

PLANETARY AND SPACE SCIENCE (2014)

Article Astronomy & Astrophysics

Jeans analysis of self-gravitating systems in f(R) gravity

S. Capozziello et al.

PHYSICAL REVIEW D (2012)

Review Physics, Multidisciplinary

Modified gravity and cosmology

Timothy Clifton et al.

PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS (2012)

Article Astronomy & Astrophysics

THE DEUTERIUM-BURNING MASS LIMIT FOR BROWN DWARFS AND GIANT PLANETS

David S. Spiegel et al.

ASTROPHYSICAL JOURNAL (2011)

Article Astronomy & Astrophysics

Chameleon mechanism with a new potential

K. Saaidi et al.

ASTROPHYSICS AND SPACE SCIENCE (2011)

Article Astronomy & Astrophysics

γ parameter and Solar System constraint in chameleon-Brans-Dicke theory

Kh. Saaidi et al.

PHYSICAL REVIEW D (2011)

Review Physics, Multidisciplinary

Extended Theories of Gravity

Salvatore Capozziello et al.

PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS (2011)

Article Physics, Multidisciplinary

Screening Long-Range Forces through Local Symmetry Restoration

Kurt Hinterbichler et al.

PHYSICAL REVIEW LETTERS (2010)

Article Astronomy & Astrophysics

Planet-bound dark matter and the internal heat of Uranus, Neptune, and hot-Jupiter exoplanets

Stephen L. Adler

PHYSICS LETTERS B (2009)

Review Astronomy & Astrophysics

Extended theories of gravity and their cosmological and astrophysical applications

Salvatore Capozziello et al.

GENERAL RELATIVITY AND GRAVITATION (2008)

Article Astronomy & Astrophysics

Models of f(R) cosmic acceleration that evade solar system tests

Wayne Hu et al.

PHYSICAL REVIEW D (2007)

Review Physics, Multidisciplinary

The theory of brown dwarfs and extrasolar giant planets

A Burrows et al.

REVIEWS OF MODERN PHYSICS (2001)