Zobrazeno 1 - 10
of 40
pro vyhledávání: '"Salo, Llibert Areste"'
In this article we calculate the reheating temperature in the cosmological scenarios where heavy scalar particles are gravitationally produced, due to a conformally coupled interaction between a massive scalar quantum field and the Ricci scalar, duri
Externí odkaz:
http://arxiv.org/abs/2411.01671
Autor:
Saló, Llibert Aresté
This thesis focuses on the application of numerical relativity methods to the solutions of problems in strong gravity. Our goal is the study of mergers of compact objects in the strong field regime where non-linear dynamics manifest and deviations fr
Externí odkaz:
http://arxiv.org/abs/2408.00044
Scalar-Gauss-Bonnet (sGB) gravity with an additional coupling between the scalar field and the Ricci scalar exhibits very interesting properties related to black hole stability, evasion of binary pulsar constraints, and general relativity as a late-t
Externí odkaz:
http://arxiv.org/abs/2404.15526
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
Autor:
de Haro, Jaume, Saló, Llibert Aresté
We present for smooth non-oscillating backgrounds an analytic formula which calculates the energy density of massive and massless particles created via gravitational particle production, thus giving the corresponding reheating temperature. It can be
Externí odkaz:
http://arxiv.org/abs/2212.01276
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
Autor:
de Haro, Jaume, Saló, Llibert Aresté
The calculation of the Bogoliubov coefficients is a key piece to obtain the reheating temperature of the Universe. In all cases this calculation is performed either in toy models where some derivative of the potential is discontinuous at some points
Externí odkaz:
http://arxiv.org/abs/2206.13854