Zobrazeno 1 - 10
of 168
pro vyhledávání: '"Figueras, Pau"'
We provide a proof that all polynomial higher-derivative effective field theories of vacuum gravity admit a well-posed initial value formulation when augmented by suitable regularising terms. These regularising terms can be obtained by field redefini
Externí odkaz:
http://arxiv.org/abs/2407.08775
Autor:
Bea, Yago, Figueras, Pau
In recent years the equations of relativistic first-order viscous hydrodynamics, that is, the relativistic version of Navier-Stokes, have been shown to be well posed and causal under appropriate field redefinitions, also known as hydrodynamic frames.
Externí odkaz:
http://arxiv.org/abs/2312.16671
Autor:
Figueras, Pau, Rossi, Lorenzo
Generic scalar perturbations on a fixed slowly rotating Kerr-AdS black hole background exhibit stable trapping, that is, the scalar field remains in a region between the exterior of the black hole and the AdS boundary for a very long time, decaying o
Externí odkaz:
http://arxiv.org/abs/2311.14167
Autor:
Saló, Llibert Aresté, Brady, Sam E., Clough, Katy, Doneva, Daniela, Evstafyeva, Tamara, Figueras, Pau, França, Tiago, Rossi, Lorenzo, Yao, Shunhui
Publikováno v:
J.Open Source Softw. 9 (2024) 98, 6369
GRFolres is an open-source code for performing simulations in modified theories of gravity, based on the publicly available 3+1D numerical relativity code GRChombo. Note: Submitted for review in the Journal of Open Source Software; Comments welcome;
Externí odkaz:
http://arxiv.org/abs/2309.06225
Modified gravity theories such as Einstein scalar Gauss Bonnet (EsGB) contain higher derivative terms in the spacetime curvature in their action, which results in modifications to the Hamiltonian and momentum constraints of the theory. In principle,
Externí odkaz:
http://arxiv.org/abs/2308.16791
Autor:
Doneva, Daniela D., Saló, Llibert Aresté, Clough, Katy, Figueras, Pau, Yazadjiev, Stoytcho S.
Quadratic theories of gravity with second order equations of motion provide an interesting model for testing deviations from general relativity in the strong gravity regime. However, they can suffer from a loss of hyperbolicity, even for initial data
Externí odkaz:
http://arxiv.org/abs/2307.06474
We develop a modified CCZ4 formulation of the Einstein equations in $d+1$ spacetime dimensions for general relativity plus a Gauss-Bonnet term, as well as for the most general parity-invariant scalar-tensor theory of gravity up to four derivatives. W
Externí odkaz:
http://arxiv.org/abs/2306.14966
Publikováno v:
Phys. Rev. Lett. 131, 111403 Published 15 September 2023
The majority of extensions to General Relativity display mathematical pathologies (higher derivatives, character change in equations that can be classified within PDE theory, and even unclassifiable ones) that cause severe difficulties to study them,
Externí odkaz:
http://arxiv.org/abs/2303.07246
We reproduce and extend the previous studies of Lehner and Pretorius of the endpoint of the Gregory-Laflamme instability of black strings in five space-time dimensions. We consider unstable black strings of fixed thickness and different lengths, and
Externí odkaz:
http://arxiv.org/abs/2210.13501
We show that the most general scalar-tensor theory of gravity up to four derivatives in $3+1$ dimensions is well-posed in a modified version of the CCZ4 formulation of the Einstein equations in singularity-avoiding coordinates. We demonstrate the rob
Externí odkaz:
http://arxiv.org/abs/2208.14470