Información del autor
Autor Cruz Dombriz, Álvaro de la |
Documentos disponibles escritos por este autor (40)
texto impreso
Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Dunsby, Dunsby ; Méndez-Isla, Miguel | Elsevier Science BV | 2019-03-10In the context of brane-world extra-dimensional theories, we compute the positron production from branon dark matter annihilations and compare with the AMS-02 data. Three different scenarios have been considered; the first two assume that either[...]texto impreso
Beltrán Jiménez, José ; Cruz Dombriz, Álvaro de la ; Dunsby, Peter K. S. ; Sáez Gómez, Diego | IOP publishing ltd | 2014-05-21One possible explanation for the present observed acceleration of the Universe is the breakdown of homogeneity and isotropy due to the formation of non-linear structures. How inhomogeneities affect the averaged cosmological expansion rate and le[...]texto impreso
Cruz Dombriz, Álvaro de la ; Sáez Gómez, Diego | Multidisciplinary Digital Publishing Institute | 2012-09-18Along this review, we focus on the study of several properties of modified gravity theories, in particular on black-hole solutions and its comparison with those solutions in General Relativity, and on Friedmann-Lemaitre-Robertson-Walker metrics.[...]texto impreso
Cruz Dombriz, Álvaro de la ; Dobado González, Antonio ; López Maroto, Antonio | American Physical Society | 2009-12In the context of f(R) theories of gravity, we address the problem of finding static and spherically symmetric black hole solutions. Several aspects of constant curvature solutions with and without electric charge are discussed. We also study th[...]texto impreso
Dobado González, Antonio ; Cruz Dombriz, Álvaro de la ; López Maroto, Antonio | IOP publishing ltd | 2010In the context of f(R) gravity theories, the issue of finding static and spherically symmetric black hole solutions is addressed. Two approaches to study the existence of such solutions are considered: first, constant curvature solutions, and s[...]texto impreso
Bourhrous, Hassan ; Cruz Dombriz, Álvaro de la ; Dunsby, Peter | American Institute of Physics | 2012We present a description of CMB anisotropies generated by tensor perturbations in f(R) theories of gravity. The temperature power spectrum in the special case of f(R) = Rn is computed using a modified version of CAMB package.texto impreso
texto impreso
Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Olano Garcia, Leandro | American Physical Society | 2013-12-15In the context of scalar-tensor theories we study the evolution of the density contrast for Jordan-Fierz-Brans-Dicke theories in a Friedmann-Lemaitre-Robertson-Walker universe. Calculations are performed in the Einstein frame with the cosmologic[...]texto impreso
Cruz Dombriz, Álvaro de la ; Dobado González, Antonio ; López Maroto, Antonio | Amer Inst Physics | 2009In the context of f(R) theories of gravity, we study the cosmological evolution of scalar perturbations by using a completely general procedure. We find that the exact fourth-order differential equation for the matter density perturbations in th[...]texto impreso
Abdelwahab, Mohamed ; Cruz Dombriz, Álvaro de la ; Dunsby, P.K.S. | American Institute of Physics | 2013We study for the first time a complete analysis of the imprint of tensor anisotropies on the Cosmic Microwave Background for a class of f(R) gravity theories within the CAMB-PPF framework. Herein we present the most relevant equations, both for [...]texto impreso
Abebe, Amare ; Abdelwahab, Mohamed ; Cruz Dombriz, Álvaro de la ; Dunsby, Peter K. S. | Institute of Physics | 2012-07-07We study the evolution of scalar cosmological perturbations in the 1 + 3 covariant gauge-invariant formalism for generic f(R) theories of gravity. Extending previous works, we give a complete set of equations describing the evolution of matter a[...]texto impreso
López Maroto, Antonio ; Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Gammaldi, Viviana | American Physical Society | 2012-02-07Branons are new degrees of freedom that appear in flexible brane-world models corresponding to brane fluctuations. These new fields can behave as standard weakly interacting massive particles (WIMPs) with a significant associated thermal relic d[...]texto impreso
Alvarenga, F. G. ; Cruz Dombriz, Álvaro de la ; Houndjo, M. J. S. ; Rodrigues, M. E. ; Sáez Gómez, Diego | American Physical Society | 2013-05-28In the context of f(R, T) theories of gravity, we study the evolution of scalar cosmological perturbations in the metric formalism. According to restrictions on the background evolution, a specific model within these theories is assumed in order[...]texto impreso
texto impreso
Cruz Dombriz, Álvaro de la ; Dobado González, Antonio ; López Maroto, Antonio | Amer Physical Soc | 2011-01-25texto impreso
Cruz Dombriz, Álvaro de la ; Dobado González, Antonio ; López Maroto, Antonio | American Physical Society | 2008-06In the context of f(R) theories of gravity, we study the evolution of scalar cosmological perturbations in the metric formalism. Using a completely general procedure, we find the exact fourth-order differential equation for the matter density pe[...]texto impreso
In this work we consider the possibility of describing the current evolution of the universe, without the introduction of any cosmological constant or dark energy (DE), by modifying the Einstein-Hilbert (EH) action. In the context of the f(R) gr[...]texto impreso
Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Dobado González, Antonio ; Lineros, R. ; López Maroto, Antonio | IOP publishing ltd | 2011Annihilation of different dark matter (DM) candidates into Standard Model (SM) particles could be detected through their contribution to the gamma ray fluxes that are measured on the Earth. The magnitude of such contributions depends on the part[...]texto impreso
Albareti, F. D. ; Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la | IOP Publishing | 2012-12-14We study the accelerated expansion of the Universe through its consequences on a congruence of geodesics. We make use of the Raychaudhuri equation which describes the evolution of the expansion rate for a congruence of timelike or null geodesics[...]texto impreso
Weltman, A. ; Bull, P. ; Camera, S. ; Kelley, K. ; Padmanabhan, H. ; Pritchard, J. ; Raccanelli, A. ; Riemer-Sorensen, S. ; Shao, L. ; Andrianomena, S. ; Athanassoula, E. ; Bacon, D. ; Barkana, R. ; Bertone, G. ; Boehm, C. ; Bonvin, C. ; Bosma, A. ; Brueggen, M. ; Burigana, C. ; Calore, F. ; Ruiz Cembranos, José Alberto ; Clarkson, C. ; Connors, R. M. T. ; Cruz Dombriz, Álvaro de la ; Dunsby, P. K. S. ; Fonseca, J. ; Fornengo, N. ; Gaggero, D. ; Harrison, I. ; Larena, J. ; Ma, Y-Z. ; Maartens, R. ; Mendez Isla, M. ; Mohanty, S. D. ; Murray, S. ; Parkinson, D. ; Pourtsidou, A. ; Quinn, P. J. ; Regis, M. ; Saha, P. ; Sakellariadou, M. ; Silk, J. ; Trombetti, T. ; Vazza, F. ; Venumadhav, T. ; Vidotto, F. ; Villaescusa Navarro, F. ; Wang, Y. ; Weniger, C. ; Wolz, L. ; Zhang, F. ; Gaensler, B. M. | Cambridge Univ Press | 2020The Square Kilometre Array (SKA) is a planned large radio interferometer designed to operate over a wide range of frequencies, and with an order of magnitude greater sensitivity and survey speed than any current radio telescope. The SKA will add[...]texto impreso
Gammaldi, Viviana ; Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Lineros, Roberto A. ; López Maroto, Antonio | Elsevier | 2015We present a study of the Galactic Center region as a possible source of both secondary gamma-ray and neutrino fluxes from annihilating dark matter. We have studied the gamma-ray flux observed by the High Energy Stereoscopic System (HESS) from t[...]texto impreso
Gammaldi, Viviana ; Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Lineros, R.A. ; López Maroto, Antonio | Elsevier | 2015We present a study of the Galactic Center region as a possible source of both secondary gamma-ray and neutrino fluxes from annihilating dark matter. We have studied the gamma-ray flux observed by the High Energy Stereoscopic System (HESS) from t[...]texto impreso
Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Montes Núñez, Bárbara | IOP Publishing | 2012-04We study the gravitational collapse in modified gravitational theories. In particular, we analyze a general f(R) model with uniformly collapsing cloud of self-gravitating dust particles. This analysis shares analogies with the formation of large[...]texto impreso
López Maroto, Antonio ; Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Gammaldi, Viviana | Amer Inst Physics | 2012If the present dark matter in the Universe annihilates into Standard Model particles, it must contribute to the gamma ray fluxes detected on the Earth. Here we briefly review the present constraints for the detection of gamma ray photons produce[...]texto impreso
Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Dobado González, Antonio ; López Maroto, Antonio | IOP publishing ltd | 2008-10One of the most striking features found in the cosmic microwave background data is the presence of an anomalous cold spot (CS) in the temperature maps made by the Wilkinson Microwave Anisotropy Probe (WMAP). This CS has been interpreted as the r[...]texto impreso
Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Dobado González, Antonio ; López Maroto, Antonio | IOP publishing ltd | 2008-10One of the most striking features found in the cosmic microwave background data is the presence of an anomalous cold spot (CS) in the temperature maps made by the Wilkinson Microwave Anisotropy Probe (WMAP). This CS has been interpreted as the r[...]texto impreso
In the context of f(R) modified gravity theories, we study the Kerr-Newman black hole solutions. We study nonzero constant scalar curvature solutions and discuss the metric tensor that satisfies the modified field equations. We conclude that, in[...]texto impreso
Abebe, Amare ; Cruz Dombriz, Álvaro de la ; Dunsby, Peter K. S. | American Physical Society | 2013-08-26Over the past few years much attention has been given to the study of modified gravity theories in order to find a more natural explanation for the late time acceleration of the Universe. Nevertheless, a comparison of the matter power spectrum p[...]texto impreso
Jimeno Romero, Pablo ; Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la | American Institute of Physics | 2012-07In the context of f(R) modified gravity theories we determine that the black holes existence is determined by the sign of a parameter dependent of the mass, the charge, the spin and the scalar curvature. We obtain the different astrophysical obj[...]texto impreso
Aparicio Resco, Miguel ; Cruz Dombriz, Álvaro de la ; Llanes Estrada, Felipe José ; Zapatero Castrillo, Víctor | Elsevier B.V. | 2016-09In the context of f(R) gravity theories, we show that the apparent mass of a neutron star as seen from an observer at infinity is numerically calculable but requires careful matching, first at the star’s edge, between interior and exterior solut[...]texto impreso
Aparicio Resco, Miguel ; Cruz Dombriz, Álvaro de la ; Llanes Estrada, Felipe José ; Zapatero Castrillo, Víctor | Elsevier B.V. | 2016-09In the context of ƒ (R) gravity theories, we show that the apparent mass of a neutron star as seen from an observer at infinity is numerically calculable but requires careful matching, first at the star’s edge, between interior and exterior solu[...]texto impreso
Albareti, F. D. ; Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Dobado González, Antonio | IOP publishing ltd | 2013-07Raychaudhuri equation is found provided that particular energy conditions are assumed and regardless the considered solution of the Einstein's equations. This fact is usually interpreted as a manifestation of the attractive character of gravity.[...]texto impreso
Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Dobado González, Antonio ; Lineros, R. ; López Maroto, Antonio | Amer Inst Physics | 2011If the present dark matter (DM) in the Universe annihilates into Standard Model (SM) particles, it must contribute to the gamma ray fluxes that are detected on the Earth. The magnitude of such contribution depends on the particular DM candidate,[...]texto impreso
Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Dobado González, Antonio ; Lineros, R.A. ; López Maroto, Antonio | Amer Physical Soc | 2011-04-11If the present dark matter in the Universe annihilates into standard model particles, it must contribute to the fluxes of cosmic rays that are detected on the Earth and, in particular, to the observed gamma-ray fluxes. The magnitude of such a co[...]texto impreso
Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Jarillo Díaz, Javier | IOP Publishing | 2015-02We study electric and magnetic monopoles in static, spherically symmetric and constant curvature geometries in the context of the inverse electrodynamics model. We prove that this U(1) invariant Lagrangian density is able to support the standard[...]texto impreso
López Maroto, Antonio ; Cruz Dombriz, Álvaro de la ; Ruiz Cembranos, José Alberto ; Gammaldi, Viviana ; Lineros, Roberto A. | Springer | 2013-09-13We study the differences in the gamma-ray spectra simulated by four Monte Carlo event generator packages developed in particle physics. Two different versions of PYTHIA and two of HERWIG are analyzed, namely PYTHIA 6.418 and HERWIG 6.5.10 in For[...]texto impreso
Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Gammaldi, Viviana ; Mendez Isla, Miguel | Elsevier B.V. | 2020-01In the era of radio astronomy, the high sensitivity of the Square Kilometre Array (SKA) could play a decisive role in the detection of new radio sources. In this work, we study the SKA sensitivity to the synchrotron radio emission expected by th[...]texto impreso
Cruz Dombriz, Álvaro de la | Universidad Complutense de Madrid, Servicio de Publicaciones | 2010-04-22En esta tesis se han estudiado algunas consecuencias cosmológicas y astrofísicas en dos teorías de gravedad modificada : las teorías f(R) y las teorías en el mundo brana en dimensiones extra. En primer lugar, hemos mostrado algunos resultados pa[...]texto impreso
Albareti, F. D. ; Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Dobado González, Antonio | IOP Publishing | 2014In this work we address the issue of studying the conditions required to guarantee the Focusing Theorem for both null and time like geodesic congruences by using the Raychaudhuri equation. In particular we study the case of Friedmann-Robertson-W[...]texto impreso
Cruz Dombriz, Álvaro de la ; Montero, Miguel ; Shahbazi Alonso, Carlos | American Physical Society | 2014-03-05A new general class of solutions of ungauged four-dimensional supergravity, in one-to-one correspondence with spherically symmetric, static black-hole solutions and Lifshitz solutions with hyperscaling violation is studied. The causal structure [...]