Jorge Páramos
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Research Interests
Jorge Páramos has a total of 143 co-authors. Here are the top co-authors by number of shared publications:
- Orfeu Bertolami
Departamento de Física e Astronomia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal
69 shared publications - Paulo J. S. Gil
CCTAE, IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
14 shared publications - Frederico Francisco
Departamento de Física e Astronomia and Centro de Física do Porto Faculdade de Ciências Universidade do Porto Rua do Campo Alegre 687 4169-007 Porto Portugal
12 shared publications - Pedro Frazão
Instituto de Plasmas e Fusão Nuclear Instituto Superior Técnico Universidade Técnica de Lisboa Av. Rovisco Pais 1 1049-001 Lisboa Portugal
7 shared publications - Riccardo March
Istituto per le Applicazioni del Calcolo
7 shared publications P. Touboul
ONERA - The French Aerospace Lab
4 shared publications
Latest Publications
- 5 May 2020
- Published by Springer Nature in General Relativity and Gravitation
- Vol. 52 (5) , 1-7
Using a non-minimal coupling between matter and curvature to sequester the cosmological constant
- 5 May 2020
- Published by Springer Nature in General Relativity and Gravitation
- Vol. 52 (5) , 1-7
Using a non-minimal coupling between matter and curvature to sequester the cosmological constant
- Open Access
- 1 January 2018
- Published by IOP Publishing in Journal of Physics: Conference Series
- Vol. 952 (1) , 012007
Inflation with a massive vector field nonminimally coupled to gravity
The possibility that inflation is driven by a massive vector field with SO(3) global symmetry nonminimally coupled to gravity is presented. Through an appropriate Ansatz for the vector field, the behaviour of the equations of motion is studied through the ensuing dynamical system, focusing on the characterisation of the ensuing fixed points.
- 1 January 2018
- Published by IOP Publishing in Journal of Physics: Conference Series
- Vol. 952 (1) , 012007
Open AccessInflation with a massive vector field nonminimally coupled to gravity
The possibility that inflation is driven by a massive vector field with SO(3) global symmetry nonminimally coupled to gravity is presented. Through an appropriate Ansatz for the vector field, the behaviour of the equations of motion is studied through the ensuing dynamical system, focusing on the characterisation of the ensuing fixed points.
- 14 December 2017
- Published by IOP Publishing in Classical and Quantum Gravity
- Vol. 35 (2) , 025002
Visible and dark matter profiles in a non-minimally coupled model
A previous work found that a nonminimally coupled theory of gravity can, under appropriate conditions, give rise to an additional contribution to the field equations interpreted as dark matter (Bertolami and Páramos 2010 J. Cosmol. Astropart. Phys . JCAP10(2010)03): in particular, the density of this dark matter component was found to scale as a power of the density of visible matter. However, no explicit solution for the modified field equations was provided, so that a direct computation of the specific density profile followed by visible matter is missing. This question is now addressed: analytical solutions to the modified field equations are derived in the appropriate perturbative regime and characterised, with an emphasis on directly obtaining the visible matter profile in a self-consistent way. We compare with known profiles for visible and dark matter and obtain constraints on the parameters of the model.
- 14 December 2017
- Published by IOP Publishing in Classical and Quantum Gravity
- Vol. 35 (2) , 025002
Visible and dark matter profiles in a non-minimally coupled model
A previous work found that a nonminimally coupled theory of gravity can, under appropriate conditions, give rise to an additional contribution to the field equations interpreted as dark matter (Bertolami and Páramos 2010 J. Cosmol. Astropart. Phys . JCAP10(2010)03): in particular, the density of this dark matter component was found to scale as a power of the density of visible matter. However, no explicit solution for the modified field equations was provided, so that a direct computation of the specific density profile followed by visible matter is missing. This question is now addressed: analytical solutions to the modified field equations are derived in the appropriate perturbative regime and characterised, with an emphasis on directly obtaining the visible matter profile in a self-consistent way. We compare with known profiles for visible and dark matter and obtain constraints on the parameters of the model.
- Open Access
Visible and Dark Matter Profiles in a Non-Minimally Coupled Model
A previous work found that a nonminimally coupled theory of gravity can, under appropriate conditions, give rise to an additional contribution to the field equations interpreted as dark matter [1]: in particular, the density of this dark matter component was found to scale as a power of the density of visible matter. However, no explicit solution for the modified field equations was provided, so that a direct computation of the specific density profile followed by visible matter is missing. This question is now addressed: analytical solutions to the modified field equations are derived in the appropriate perturbative regime and characterised, with an emphasis on directly obtaining the visible matter profile in a self-consistent way. We compare with known profiles for visible and dark matter and obtain constraints on the parameters of the model.
Open AccessVisible and Dark Matter Profiles in a Non-Minimally Coupled Model
A previous work found that a nonminimally coupled theory of gravity can, under appropriate conditions, give rise to an additional contribution to the field equations interpreted as dark matter [1]: in particular, the density of this dark matter component was found to scale as a power of the density of visible matter. However, no explicit solution for the modified field equations was provided, so that a direct computation of the specific density profile followed by visible matter is missing. This question is now addressed: analytical solutions to the modified field equations are derived in the appropriate perturbative regime and characterised, with an emphasis on directly obtaining the visible matter profile in a self-consistent way. We compare with known profiles for visible and dark matter and obtain constraints on the parameters of the model.
- Open AccessBaryogenesis in Nonminimally Coupled $f(R)$ TheoriesWe generalize the mechanism for gravitational baryogensis in the context of $f(R)$ theories of gravity, including a nonminimal coupling between curvature and matter. In these models, the baryon asymmetry is generated through an effective coupling between the Ricci scalar curvature and the net baryon current that dynamically breaks Charge Conjugation, Parity and Time Reversal (CPT) invariance. We study the combinations of characteristic mass scales and exponents for both non-trivial functions present in the modified action functional and establish the allowed region for these parameters: we find that very small deviations from General Relativity are consistent with the observed baryon asymmetry and lead to temperatures compatible with the subsequent formation of the primordial abundances of light elements. In particular, we show the viability of a power-law nonminimal coupling function $f_2(R) \sim R^n$ with $ 0 < n \lesssim 0.078 $ and determine its characteristic curvature scale.Open AccessBaryogenesis in Nonminimally Coupled $f(R)$ TheoriesWe generalize the mechanism for gravitational baryogensis in the context of $f(R)$ theories of gravity, including a nonminimal coupling between curvature and matter. In these models, the baryon asymmetry is generated through an effective coupling between the Ricci scalar curvature and the net baryon current that dynamically breaks Charge Conjugation, Parity and Time Reversal (CPT) invariance. We study the combinations of characteristic mass scales and exponents for both non-trivial functions present in the modified action functional and establish the allowed region for these parameters: we find that very small deviations from General Relativity are consistent with the observed baryon asymmetry and lead to temperatures compatible with the subsequent formation of the primordial abundances of light elements. In particular, we show the viability of a power-law nonminimal coupling function $f_2(R) \sim R^n$ with $ 0 < n \lesssim 0.078 $ and determine its characteristic curvature scale.
- 16 November 2017
- Published by American Physical Society (APS) in Physical Review D
- Vol. 96 (10) , 104024
Baryogenesis in nonminimally coupled theoriesWe generalize the mechanism for gravitational baryogensis in the context of theories of gravity, including a nonminimal coupling between curvature and matter. In these models, the baryon asymmetry is generated through an effective coupling between the Ricci scalar curvature and the net baryon current that dynamically breaks Charge conjugation, parity and time reversal () invariance. We study the combinations of characteristic mass scales and exponents for both nontrivial functions present in the modified action functional and establish the allowed region for these parameters: we find that very small deviations from general relativity are consistent with the observed baryon asymmetry and lead to temperatures compatible with the subsequent formation of the primordial abundances of light elements. In particular, we show the viability of a power-law nonminimal coupling function with and determine its characteristic curvature scale.- 16 November 2017
- Published by American Physical Society (APS) in Physical Review D
- Vol. 96 (10) , 104024
Baryogenesis in nonminimally coupled theoriesWe generalize the mechanism for gravitational baryogensis in the context of theories of gravity, including a nonminimal coupling between curvature and matter. In these models, the baryon asymmetry is generated through an effective coupling between the Ricci scalar curvature and the net baryon current that dynamically breaks Charge conjugation, parity and time reversal () invariance. We study the combinations of characteristic mass scales and exponents for both nontrivial functions present in the modified action functional and establish the allowed region for these parameters: we find that very small deviations from general relativity are consistent with the observed baryon asymmetry and lead to temperatures compatible with the subsequent formation of the primordial abundances of light elements. In particular, we show the viability of a power-law nonminimal coupling function with and determine its characteristic curvature scale.- 13 January 2017
- Published by American Physical Society (APS) in Physical Review D
- Vol. 95 (2) , 024017
expansion of nonminimally coupled curvature-matter gravity models and constraints from planetary precessionThe effects of a nonminimally coupled curvature-matter model of gravity on a perturbed Minkowski metric are presented. The action functional of the model involves two functions and of the Ricci scalar curvature . This work expands upon previous results, extending the framework developed there to compute corrections up to order of the 00 component of the metric tensor. It is shown that additional contributions arise due to both the nonlinear form and the nonminimal coupling , including exponential contributions that cannot be expressed as an expansion in powers of . Some possible experimental implications are assessed with application to perihelion precession.- 13 January 2017
- Published by American Physical Society (APS) in Physical Review D
- Vol. 95 (2) , 024017
expansion of nonminimally coupled curvature-matter gravity models and constraints from planetary precessionThe effects of a nonminimally coupled curvature-matter model of gravity on a perturbed Minkowski metric are presented. The action functional of the model involves two functions and of the Ricci scalar curvature . This work expands upon previous results, extending the framework developed there to compute corrections up to order of the 00 component of the metric tensor. It is shown that additional contributions arise due to both the nonlinear form and the nonminimal coupling , including exponential contributions that cannot be expressed as an expansion in powers of . Some possible experimental implications are assessed with application to perihelion precession.- Open Access
Cosmological dynamics of a class of non-minimally coupled models of gravity
In this work a new non-minimally coupled model is presented, where a generic function $f(R)$ of the scalar curvature factors the usual Einstein-Hilbert action functional, motivated by relevant results obtained from similar models. Its cosmological dynamics are derived and the possibility of attaining a phase of accelerated expansion is assessed. To further probe the possible implications of the model, a dynamical system formulation is established, and used to assess the scenarios where $f(R)$ assumes a power-law or exponential form.Open AccessCosmological dynamics of a class of non-minimally coupled models of gravity
In this work a new non-minimally coupled model is presented, where a generic function $f(R)$ of the scalar curvature factors the usual Einstein-Hilbert action functional, motivated by relevant results obtained from similar models. Its cosmological dynamics are derived and the possibility of attaining a phase of accelerated expansion is assessed. To further probe the possible implications of the model, a dynamical system formulation is established, and used to assess the scenarios where $f(R)$ assumes a power-law or exponential form. - 13 September 2016
- Published by American Physical Society (APS) in Physical Review D
- Vol. 94 (6) , 064036
Dynamical analysis of generalizedtheoriesIn this work, we use a dynamical system approach to analyze the viability of candidates for dark energy. We compare these with nonminimal coupled theories and study the solutions for exponential and power-law forms in order to constrain the allowed range of model parameters.- 13 September 2016
- Published by American Physical Society (APS) in Physical Review D
- Vol. 94 (6) , 064036
Dynamical analysis of generalizedtheoriesIn this work, we use a dynamical system approach to analyze the viability of candidates for dark energy. We compare these with nonminimal coupled theories and study the solutions for exponential and power-law forms in order to constrain the allowed range of model parameters.- Open AccessDynamical analysis of generalised $f(R,\mathcal{L})$ theoriesIn this work, we use a dynamical system approach to analyse the viability of $f(R,\mathcal{L})$ candidates for dark energy. We compare these with nonminimal coupled $f(R)$ theories and study the solutions for exponential and power-law forms in order to constraint the allowed range of model parameters.Open AccessDynamical analysis of generalised $f(R,\mathcal{L})$ theoriesIn this work, we use a dynamical system approach to analyse the viability of $f(R,\mathcal{L})$ candidates for dark energy. We compare these with nonminimal coupled $f(R)$ theories and study the solutions for exponential and power-law forms in order to constraint the allowed range of model parameters.