Zobrazeno 1 - 10
of 754
pro vyhledávání: '"Fethi M"'
We show that higher form fields, specifically 2- and 3-forms in four spacetime dimensions, suffer from loss of hyperbolicity when they have self interaction. The equations of motion lose their wave-like characteristic in certain parts of the configur
Externí odkaz:
http://arxiv.org/abs/2406.15321
Autor:
Coates, Andrew, Ramazanoğlu, Fethi M.
Publikováno v:
Phys. Rev. D 108, L101501 (2023)
We demonstrate some shortcomings of "fixing the equations," an increasingly popular remedy for time evolution problems of effective field theories (EFTs). We compare the EFTs and their "fixed" versions to the UV theories from which they can be derive
Externí odkaz:
http://arxiv.org/abs/2307.07743
Publikováno v:
Phys. Rev. D 108, 044022 (2023)
Various groups recently demonstrated that the time evolution of simplest self-interacting vector fields, those with self-interaction potentials, can break down after a finite duration in what is called loss of hyperbolicity. We establish that this is
Externí odkaz:
http://arxiv.org/abs/2306.03554
Simultaneous measurements of neutron star masses and radii can be used to constrain deviations from general relativity (GR) as was recently demonstrated for the spontaneous scalarization model of Damour and Esposito-Far\`{e}se (DEF). Here, we investi
Externí odkaz:
http://arxiv.org/abs/2303.01910
Autor:
Coates, Andrew, Ramazanoğlu, Fethi M.
Publikováno v:
Phys. Rev. D 107, 104036 (2023)
Various groups recently argued that self-interacting vector field theories lack a well-defined time evolution when the field grows to large amplitudes, which has drastic consequences for models in gravity and high energy theory. Such field amplitudes
Externí odkaz:
http://arxiv.org/abs/2301.02263
Autor:
Coates, Andrew, Ramazanoğlu, Fethi M.
Publikováno v:
Phys. Rev. Lett. 130, 021401 (2023)
Self-interacting vectors are seeing a burst of interest where various groups demonstrated that the field evolution ends in finite time. Two nonequivalent criteria have been offered to identify this breakdown: (i) the vector constraint equation cannot
Externí odkaz:
http://arxiv.org/abs/2211.08027
Autor:
Doneva, Daniela D., Ramazanoğlu, Fethi M., Silva, Hector O., Sotiriou, Thomas P., Yazadjiev, Stoytcho S.
Publikováno v:
Rev. Mod. Phys. 96, 015004 (2024)
Scalarization is a mechanism that endows strongly self-gravitating bodies, such as neutron stars and black holes, with a scalar-field configuration. It resembles a phase transition in that the scalar configuration appears only when a certain quantity
Externí odkaz:
http://arxiv.org/abs/2211.01766
Autor:
Coates, Andrew, Ramazanoğlu, Fethi M.
Publikováno v:
Phys. Rev. Lett. 129, 151103 (2022)
We show that self-interacting vector field theories exhibit unphysical behaviour even when they are not coupled to any external field. This means any theory featuring such vectors is in danger of being unphysical, an alarming prospect for many propos
Externí odkaz:
http://arxiv.org/abs/2205.07784
Publikováno v:
Phys. Rev. D 105, 124070 (2022)
We use neutron star mass and radius measurements to constrain the spontaneous scalarization phenomenon in scalar-tensor theories using Bayesian analysis. Neutron star structures in this scenario can be significantly different from the case of general
Externí odkaz:
http://arxiv.org/abs/2204.02138
In recent papers it has been shown that a large class of vectorization mechanisms in gravity, which involve the vector fields becoming apparently tachyonic in some regime, are actually dominated by ghosts and non-perturbative behavior. Despite this,
Externí odkaz:
http://arxiv.org/abs/2112.04269