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Author (down) Ortega, P.G.; Entem, D.R.; Fernandez, F.
Title LHCb pentaquarks in constituent quark models Type Journal Article
Year 2017 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 764 Issue Pages 207-211
Keywords Models of strong interactions; Heavy quarkonia; Potential models
Abstract The recently discovered P-c(4380)(+) and P-c(4450)(+) states at LHCb have masses close to the (D) over bar Sigma(C)* and (D) over bar*Sigma(C) thresholds, respectively, which suggest that they may have significant meson-baryon molecular components. We analyze these states in the framework of a constituent quark model which has been applied to a wide range of hadronic observables, being the model parameters, therefore, completely constrained. The P-c(4380)(+) and P-c(4450)(+) are studied as molecular states composed by charmed baryons and open charm mesons. Several bound states with the proper binding energy are found in the (D) over bar Sigma(C)* and (D) over bar*Sigma(C) chennels. We discuss the possible assignments of these states from their decay widths. Moreover, two more states are predicted, associated with the (D) over bar Sigma(C) and (D) over bar*Sigma*(C) thresholds. (C) 2016 Published by Elsevier B.V.
Address [Ortega, P. G.] Univ Valencia, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: Pablo.Garcia@ific.uv.es;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000390127100030 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2996
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Author (down) Olmo, G.J.; Rubiera-Garcia, D.; Wojnar, A.
Title Stellar structure models in modified theories of gravity: Lessons and challenges Type Journal Article
Year 2020 Publication Physics Reports Abbreviated Journal Phys. Rep.
Volume 876 Issue Pages 1-75
Keywords Stellar structure; Modified gravity; Palatini formalism; Neutron stars; Brown dwarfs; Relativistic stars; Weak field; f(R) theories; Born-Infeld theory; Horndeski theory
Abstract The understanding of stellar structure represents the crossroads of our theories of the nuclear force and the gravitational interaction under the most extreme conditions observably accessible. It provides a powerful probe of the strong field regime of General Relativity, and opens fruitful avenues for the exploration of new gravitational physics. The latter can be captured via modified theories of gravity, which modify the Einstein-Hilbert action of General Relativity and/or some of its principles. These theories typically change the Tolman-Oppenheimer-Volkoff equations of stellar's hydrostatic equilibrium, thus having a large impact on the astrophysical properties of the corresponding stars and opening a new window to constrain these theories with present and future observations of different types of stars. For relativistic stars, such as neutron stars, the uncertainty on the equation of state of matter at supranuclear densities intertwines with the new parameters coming from the modified gravity side, providing a whole new phenomenology for the typical predictions of stellar structure models, such as mass-radius relations, maximum masses, or moment of inertia. For non-relativistic stars, such as white, brown and red dwarfs, the weakening/strengthening of the gravitational force inside astrophysical bodies via the modified Newtonian (Poisson) equation may induce changes on the star's mass, radius, central density or luminosity, having an impact, for instance, in the Chandrasekhar's limit for white dwarfs, or in the minimum mass for stable hydrogen burning in high-mass brown dwarfs. This work aims to provide a broad overview of the main such results achieved in the recent literature for many such modified theories of gravity, by combining the results and constraints obtained from the analysis of relativistic and non-relativistic stars in different scenarios. Moreover, we will build a bridge between the efforts of the community working on different theories, formulations, types of stars, theoretical modelings, and observational aspects, highlighting some of the most promising opportunities in the field.
Address [Olmo, Gonzalo J.] Univ Valencia, Dept Fis Teor, Ctr Mixto, CSIC, Valencia 46100, Spain, Email: gonzalo.olmo@uv.es;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-1573 ISBN Medium
Area Expedition Conference
Notes WOS:000570298900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4531
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Author (down) Olmo, G.J.; Rubiera-Garcia, D.; Saez-Chillon Gomez, D.
Title New light rings from multiple critical curves as observational signatures of black hole mimickers Type Journal Article
Year 2022 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 829 Issue Pages 137045 - 5pp
Keywords
Abstract We argue that the appearance of additional light rings in a shadow observation – beyond the infinite sequence of exponentially demagnified self-similar rings foreseen in the Kerr solution – would make a compelling case for the existence of black hole mimickers having multiple critical curves. We support this claim by discussing three different scenarios of spherically symmetric wormhole geometries having two such critical curves, and explicitly work out the optical appearance of one such object when surrounded by an optically and geometrically thin accretion disk.
Address [Olmo, Gonzalo J.] Univ Valencia, CSIC, Ctr Mixto Univ Valencia, Dept Fis Teor, Valencia 46100, Spain, Email: gonzalo.olmo@uv.es;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000821533700007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5290
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Author (down) Olmo, G.J.; Rubiera-Garcia, D.
Title Nonsingular Charged Black Holes A La Palatini Type Journal Article
Year 2012 Publication International Journal of Modern Physics D Abbreviated Journal Int. J. Mod. Phys. D
Volume 21 Issue 8 Pages 1250067 - 6pp
Keywords Extended theories of gravity; Palatini formalism; Planck scale
Abstract We argue that the quantum nature of matter and gravity should lead to a discretization of the allowed states of the matter confined in the interior of black holes. To support and illustrate this idea, we consider a quadratic extension of general relativity (GR) formulated a la Palatini and show that nonrotating, electrically charged black holes develop a compact core at the Planck density which is nonsingular if the mass spectrum satisfies a certain discreteness condition. We also find that the area of the core is proportional to the number of charges times the Planck area.
Address [Olmo, Gonzalo J.] Univ Valencia, CSIC, Dept Fis Teor, Fac Fis, E-46100 Valencia, Spain
Corporate Author Thesis
Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0218-2718 ISBN Medium
Area Expedition Conference
Notes WOS:000308497500002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1154
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Author (down) Olmo, G.J.; Rubiera-Garcia, D.
Title Semiclassical geons at particle accelerators Type Journal Article
Year 2014 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 02 Issue 2 Pages 010 - 25pp
Keywords modified gravity; Wormholes; quantum black holes
Abstract We point out that in certain four-dimensional extensions of general relativity constructed within the Palatini formalism stable self-gravitating objects with a discrete mass and charge spectrum may exist. The incorporation of nonlinearities in the electromagnetic field may effectively reduce their mass spectrum by many orders of magnitude. As a consequence, these objects could be within (or near) the reach of current particle accelerators. We provide an exactly solvable model to support this idea.
Address [Omla, Gonzalo J.] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@csic.es;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000332711400010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1733
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Author (down) Olmo, G.J.; Rubiera-Garcia, D.
Title Brane-world and loop cosmology from a gravity-matter coupling perspective Type Journal Article
Year 2015 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 740 Issue Pages 73-79
Keywords Modified gravity; Palatini formalism; f(R) theories; Gravity-matter coupling; Quadratic cosmology
Abstract We show that the effective brane-world and the loop quantum cosmology background expansion histories can be reproduced from a modified gravity perspective in terms of an f (R) gravity action plus a g(R) term non-minimally coupled with the matter Lagrangian. The reconstruction algorithm that we provide depends on a free function of the matter density that must be specified in each case and allows to obtain analytical solutions always. In the simplest cases, the function f (R) is quadratic in the Ricci scalar, R, whereas g(R) is linear. Our approach is compared with recent results in the literature. We show that working in the Palatini formalism there is no need to impose any constraint that keeps the equations second order, which is a key requirement for the successful implementation of the reconstruction algorithm.
Address [Olmo, Gonzalo J.] Univ Valencia, CSIC, Ctr Mixto, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@csic.es;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000347046200013 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2099
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Author (down) Olmo, G.J.; Rubiera-Garcia, D.
Title The quantum, the geon and the crystal Type Journal Article
Year 2015 Publication International Journal of Modern Physics D Abbreviated Journal Int. J. Mod. Phys. D
Volume 24 Issue 9 Pages 1542013 - 15pp
Keywords Effective geometries; crystalline structures; modified gravity; metric-affine approach; geons
Abstract Effective geometries arising from a hypothetical discrete structure of spacetime can play an important role in the understanding of the gravitational physics beyond General Relativity (GR). To discuss this question, we make use of lessons from crystalline systems within solid state physics, where the presence of defects in the discrete microstructure of the crystal determine the kind of effective geometry needed to properly describe the system in the macroscopic continuum limit. In this work, we study metric-affine theories with nonmetricity and torsion, which are the gravitational analog of crystalline structures with point defects and dislocations. We consider a crystal-motivated gravitational action and show the presence of topologically nontrivial structures (wormholes) supported by an electromagnetic field. Their existence has important implications for the quantum foam picture and the effective gravitational geometries. We discuss how the dialogue between solid state physics systems and modified gravitational theories can provide useful insights on both sides.
Address [Olmo, Gonzalo J.] Univ Valencia, CSIC, Fac Fis, Dept Fis Teor, E-46100 Valencia, Spain, Email: drubiera@fudan.edu.cn
Corporate Author Thesis
Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0218-2718 ISBN Medium
Area Expedition Conference
Notes WOS:000358793200014 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2322
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Author (down) Olmo, G.J.; Rubiera-Garcia, D.
Title Some recent results on Ricci-based gravity theories Type Journal Article
Year 2022 Publication International Journal of Modern Physics D Abbreviated Journal Int. J. Mod. Phys. D
Volume 31 Issue Pages 2240012 - 15pp
Keywords Metric-affine gravity; scalar fields; stellar models; junction conditions; compact objects
Abstract In this paper, metric-afline theories in which the gravity Lagrangian is built using (projectively invariant) contractions of the Ricci tensor with itself and with the metric (Ricci-based gravity theories, or RBGs for short) are reviewed. The goal is to provide a contextualized and coherent presentation of some recent results. In particular, we focus on the correspondence that exists between the field equations of these theories and those of general relativity, and comment on how this can be used to build new solutions of physical interest. We also discuss the formalism of junction conditions in the f (R) case, and provide a brief summary on current experimental and observational bounds on model parameters.
Address [Olmo, Gonzalo J.] Univ Valencia, CSIC, Ctr Mixto, Dept Fis Teor, Valencia 46100, Spain, Email: gonzalo.olmo@uv.es;
Corporate Author Thesis
Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0218-2718 ISBN Medium
Area Expedition Conference
Notes WOS:000848888900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5350
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Author (down) Olmo, G.J.; Orazi, E.; Pradisi, G.
Title Conformal metric-affine gravities Type Journal Article
Year 2022 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 10 Issue 10 Pages 057 - 21pp
Keywords Gauss-Bonnet-Lovelock-Horndeski-Palatini etc gravity theories; modified gravity
Abstract We revisit the gauge symmetry related to integrable projective transformations in metric-affine formalism, identifying the gauge field of the Weyl (conformal) symmetry as a dynamical component of the affine connection. In particular, we show how to include the local scaling symmetry as a gauge symmetry of a large class of geometric gravity theories, introducing a compensator dilaton field that naturally gives rise to a Stuckelberg sector where a spontaneous breaking mechanism of the conformal symmetry is at work to generate a mass scale for the gauge field. For Ricci-based gravities that include, among others, General Relativity, f(R) and f(R, R μnu R μnu) theories and the EiBI model, we prove that the on-shell gauge vector associated to the scaling symmetry can be identified with the torsion vector, thus recovering and generalizing conformal invariant theories in the Riemann-Cartan formalism, already present in the literature.
Address [Olmo, Gonzalo J.] Univ Valencia, Ctr Mixto, Dept Fis Teor, CSIC, Valencia 46100, Spain, Email: gonzalo.olmo@uv.es;
Corporate Author Thesis
Publisher IOP Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000878259300018 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5405
Permanent link to this record
 

 
Author (down) Olmo, G.J.
Title Palatini actions and quantum gravity phenomenology Type Journal Article
Year 2011 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 10 Issue 10 Pages 018 - 15pp
Keywords quantum gravity phenomenology; cosmic singularity
Abstract We show that an invariant an universal length scale can be consistently introduced in a generally covariant theory through the gravitational sector using the Palatini approach. The resulting theory is able to capture different aspects of quantum gravity phenomenology in a single framework. In particular, it is found that in this theory field excitations propagating with different energy-densities perceive different background metrics, which is a fundamental characteristic of the DSR and Rainbow Gravity approaches. We illustrate these properties with a particular gravitational model and explicitly show how the soccer ball problem is avoided in this framework. The isotropic and anisotropic cosmologies of this model also avoid the big bang singularity by means of a big bounce.
Address [Olmo, GJ] Univ Valencia, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@csic.es
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000296767600018 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 816
Permanent link to this record