Results 11 to 20 of about 251,804 (253)
Primordial Adiabatic Fluctuations from Cosmic Defects [PDF]
, 2000 We point out that in the context of ``two-metric'' theories of gravity there is the possibility that cosmic defects will produce a spectrum of primordial adiabatic density perturbations. This will happen when the speed characterising the defect-producing
A. Albrecht +38 more
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Non-metric geometry as the origin of mass in gauge theories of scale invariance
European Physical Journal C: Particles and Fields, 2023 We discuss gauge theories of scale invariance beyond the Standard Model (SM) and Einstein gravity. A consequence of gauging this symmetry is that their underlying 4D geometry is non-metric ( $$\nabla _\mu g_{\alpha \beta }\!\not =\!0$$ ∇ μ g α β ≠ 0 ...
D. M. Ghilencea
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Universally finite gravitational and gauge theories
Nuclear Physics B, 2015 It is well known that standard gauge theories are renormalizable in D=4 while Einstein gravity is renormalizable in D=2. This is where the research in the field of two derivatives theories is currently standing.
Leonardo Modesto, Lesław Rachwał
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Gravitational Waves: The Theorist’s Swiss Knife
Universe, 2022 Gravitational waves provide a novel and powerful way to test astrophysical models of compact objects, early universe processes, beyond the Standard Model particle physics, dark matter candidates, Einstein’s theory of General Relativity and extended ...
Mairi Sakellariadou
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Gravitational quasinormal modes of black holes in Einstein-aether theory
Nuclear Physics B, 2019 The local Lorentz violation (LV) in gravity sector should show itself in derivation of the characteristic quasinormal modes (QNMs) of black hole mergers from their general relativity case.
Chikun Ding
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Analytical amplitudes from numerical solutions of the scattering equations
Journal of High Energy Physics, 2020 The CHY formalism for massless scattering provides a cohesive framework for the computation of scattering amplitudes in a variety of theories. It is especially compelling because it elucidates existing relations among theories which are seemingly ...
Giuseppe De Laurentis
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Scaling solution for field-dependent gauge couplings in quantum gravity
Nuclear Physics B, 2022 Quantum gravity can determine the dependence of gauge couplings in a scalar field, which is related to possible fifth forces and time varying fundamental “constants”. This prediction is based on the scaling solution of functional flow equations.
C. Wetterich
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Modified gravitational-wave propagation and standard sirens [PDF]
, 2018 Studies of dark energy at advanced gravitational-wave (GW) interferometers normally focus on the dark energy equation of state $w_{\rm DE}(z)$. However, modified gravity theories that predict a non-trivial dark energy equation of state generically also ...
Belgacem, Enis +3 more
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Looking for Traces of Nonminimally Coupled Dark Matter in the X-COP Galaxy Clusters Sample
The Astrophysical Journal, 2023 We look for possible evidence of a nonminimal coupling (NMC) between dark matter (DM) and gravity using data from the X-COP compilation of galaxy clusters.
Giovanni Gandolfi +3 more
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Friction in gravitational waves: A test for early-time modified gravity
Physics Letters B, 2015 Modified gravity theories predict in general a non-standard equation for the propagation of gravitational waves. Here we discuss the impact of modified friction and speed of tensor modes on cosmic microwave polarization B modes.
Valeria Pettorino, Luca Amendola
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