Zobrazeno 1 - 10
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pro vyhledávání: '"Reyes, Carlos A."'
The incompatibility of explicit diffeomorphism violation with Riemannian geometry within the gravitational Standard-Model Extension (SME) is revisited. We review two methods of how to deal with this problem. The first is based on an approach proposed
Externí odkaz:
http://arxiv.org/abs/2407.19264
We study a general class of effective backgrounds that break diffeomorphism invariance and their potential roles in cosmology. Specifically, we examine both explicit and spontaneous background fields which display distinct transformation properties a
Externí odkaz:
http://arxiv.org/abs/2407.13041
The scalar sector of the Myers and Pospelov model is considered. This theory introduces a dimension 5 operator with a preferred four-vector which breaks Lorentz symmetry. We investigate various applications using the TFD formalism, a topological fiel
Externí odkaz:
http://arxiv.org/abs/2406.13574
Autor:
Reyes, Carlos M., Schreck, Marco
A modification of General Relativity that is based on the gravitational Standard-Model Extension and incorporates nondynamical background fields has recently been studied via the ADM formalism. Our objective in this paper is to develop a better under
Externí odkaz:
http://arxiv.org/abs/2305.07060
We investigate the preservation of unitarity in a Lorentz and CPT-violating QED model containing higher-order operators. In particular, we consider modifications in the fermion sector with dimension-five operators. The higher-order operators lead to
Externí odkaz:
http://arxiv.org/abs/2303.09689
We find sufficient conditions for bounded density shifts to have a unique measure of maximal entropy. We also prove that every measure of maximal entropy of a bounded density shift is fully supported. As a consequence of this, we obtain that bounded
Externí odkaz:
http://arxiv.org/abs/2302.07307
Autor:
Reyes, Carlos M.
The Hamiltonian formulation of the gravitational sector of the Standard-Model Extension (SME) with nondynamical fields $u$ and $s^{\mu \nu}$ is studied. We provide the relevant Hamiltonians that describe the constrained phase space and the dynamics o
Externí odkaz:
http://arxiv.org/abs/2209.09380
Higher-order effects of CPT and Lorentz violation within the SME effective framework including Myers-Pospelov dimension-five operator terms are studied. The model is canonically quantized by giving special attention to the arising of indefinite-metri
Externí odkaz:
http://arxiv.org/abs/2206.05784
We consider diffeomorphism violation, which is parameterized by nondynamical background fields of the gravitational Standard-Model Extension (SME), and study its effects on the time evolution of the Universe. Our goal is to identify background field
Externí odkaz:
http://arxiv.org/abs/2205.06329
Autor:
Reyes, Carlos M., Schreck, Marco
We study the dynamics of a modified-gravity theory, which is supplemented by an extended Gibbons-Hawking-York boundary term and incorporates diffeomorphism violation through nondynamical background fields denoted as $u$ and $s^{\mu\nu}$ in the litera
Externí odkaz:
http://arxiv.org/abs/2202.11881