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相关论文: A new helioseismic constraint on a cosmic-time var…

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We estimate the possible variations of the gravitational constant G in the framework of a generalized (Bergmann-Wagoner-Nordtvedt) scalar-tensor theory of gravity on the basis of the field equations, without using their special solutions.…

广义相对论与量子宇宙学 · 物理学 2007-05-23 K. A. Bronnikov , V. N. Melnikov , Mario Novello

We propose a method to constrain the variation of the gravitational constant $G$ with cosmic time using gravitational-wave (GW) observations of merging binary neutron stars. The method essentially relies on the fact that the maximum and…

广义相对论与量子宇宙学 · 物理学 2021-04-19 Aditya Vijaykumar , Shasvath J. Kapadia , Parameswaran Ajith

We propose helioseismology as a new, precision probe of fifth forces at astrophysical scales, and apply it on the most general scalar-tensor theories for dark energy, known as Degenerate Higher-Order Scalar-Tensor theories (DHOST). We…

宇宙学与河外天体物理 · 物理学 2019-09-11 Ippocratis D. Saltas , Ilídio Lopes

We discuss cosmology based on a Cuscuta-Galileon gravity theory, which preserves just two degrees of freedom. Although there exists no additional degrees of freedom, introduction of a potential of a scalar field changes the dynamics. The…

广义相对论与量子宇宙学 · 物理学 2022-05-17 Kei-ichi Maeda , Sirachak Panpanich

We report a constraint on the cosmological variation of the proton g-factor, $g_p$. By comparing the measured redshifts between \mbox{H\,{\sc i}} 21 cm and OH 18 cm lines observed with the newly commissioned Five-hundred-meter Aperture…

宇宙学与河外天体物理 · 物理学 2026-02-16 Renzhi Su , Stephen J. Curran , Jeremy Darling , Minfeng Gu , J. N. H. S. Aditya , Ningyu Tang , Di Li , Zheng Zheng

We perform correct and reasonable cosmological constraints on the newly proposed 4D Gauss-Bonnet gravity. Using the joint constraint from cosmic microwave background, baryon acoustic oscillations, Type Ia supernovae, cosmic chronometers and…

宇宙学与河外天体物理 · 物理学 2021-04-20 Deng Wang , David Mota

Newton's constant has observational effects on both the CMB power spectra and the light curves of SNIa. We use Planck data, BAO data and the SNIa measurement to constrain the varying Newton's constant $G$ during the CMB epoch and the…

宇宙学与河外天体物理 · 物理学 2020-07-15 Ke Wang , Lu Chen

We investigate the evolution of gravitational waves through discontinuous evolution (transition) of the Hubble expansion rate $H(z)$ at a sudden cosmological singularity, which may be due to a transition of the value of the gravitational…

宇宙学与河外天体物理 · 物理学 2023-07-04 Evangelos Achilleas Paraskevas , Leandros Perivolaropoulos

A model is presented where the quintessence parameter, w, is related to a time-varying gravitational constant. Assuming a present value of w equals -.98, we predict a current variation of G dot/G = -.06 H0. H0 is Hubbles parameter, G is…

广义相对论与量子宇宙学 · 物理学 2020-08-03 Christopher Pilot

We derive strong observational limits on any possible large-scale spatial variation in the values of physical 'constants' whose space-time evolution is driven by a scalar field. The limits are imposed by the isotropy of the microwave…

天体物理学 · 物理学 2009-11-10 John D. Barrow

AIM: To study the variation of the angular momentum and the rotational kinetic energy of the Sun, and associated variations in the gravitational multipole moments, on a timescale of the solar cycle. METHOD: Inverting helioseismic rotational…

天体物理学 · 物理学 2009-11-13 H. M. Antia , S. M. Chitre , D. O. Gough

We study the cosmological constraints on the variation of the Newton's constant and on post-Newtonian parameters for simple models of scalar-tensor theory of gravity beyond the extended Jordan-Brans-Dicke theory. We restrict ourselves to an…

宇宙学与河外天体物理 · 物理学 2020-02-07 M. Rossi , M. Ballardini , M. Braglia , F. Finelli , D. Paoletti , A. A. Starobinsky , C. Umiltà

More than 635 000 positional observations (mostly radiotechnical) of planets and spacecraft (1961-2010), have been used for estimating possible changes of the gravitation constant, the solar mass, and semi-major axes of planets, as well as…

太阳与恒星天体物理 · 物理学 2015-05-30 E. V. Pitjeva , N. P. Pitjev

Exotic cosmologies predict variability of the fundamental physical constants over the cosmic time. Using the VLT/UVES high resolution spectra of the quasar Q0347-3819 and unblended electronic - vibrational - rotational lines of the H2…

天体物理学 · 物理学 2014-10-13 S. A. Levshakov , M. Dessauges-Zavadsky , S. D'Odorico , P. Molaro

Radio-frequency E1 transitions between nearly degenerate, opposite parity levels of atomic dysprosium were monitored over an eight month period to search for a variation in the fine-structure constant. During this time period, data were…

We present new constraints on cosmic variations of Newton's gravitational constant by making use of the latest CMB data from WMAP, BOOMERANG, CBI and ACBAR experiments and independent constraints coming from Big Bang Nucleosynthesis. We…

宇宙学与河外天体物理 · 物理学 2009-08-19 Silvia Galli , Alessandro Melchiorri , George F. Smoot , Oliver Zahn

In this work, we investigate cosmologies where the gravitational constant varies in time, with the aim of explaining the accelerated expansion without a cosmological constant. We achieve this by considering a phenomenological extension to…

宇宙学与河外天体物理 · 物理学 2020-03-18 Ekim Taylan Hanımeli , Brahim Lamine , Alain Blanchard , Isaac Tutusaus

We show that the current bounds on the time variation of the Newton constant G can put severe constraints on many interesting scalar-tensor theories which possess a shift symmetry and a nonminimal matter-scalar coupling. This includes, in…

广义相对论与量子宇宙学 · 物理学 2012-01-18 Eugeny Babichev , Cedric Deffayet , Gilles Esposito-Farese

Galactic cosmic rays (GCRs) are affected by solar modulation while they propagate through the heliosphere. The study of the time variation of GCR spectra observed at Earth can shed light on the underlying physical processes, specifically…

太阳与恒星天体物理 · 物理学 2019-02-07 Claudio Corti , Marius S. Potgieter , Veronica Bindi , Cristina Consolandi , Chris Light , Matteo Palermo , Alexis Popkow

A Higgs boson mass $\sim 126$ GeV as determined by the LHC data requires a large loop correction which in turn implies a large sfermion mass. Implication of this result for the stability of the proton in supersymmetric grand unified…

高能物理 - 唯象学 · 物理学 2015-06-15 Mengxi Liu , Pran Nath