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R F L Holanda - One of the best experts on this subject based on the ideXlab platform.
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constraints on a possible variation of the fine structure constant from galaxy cluster data
Journal of Cosmology and Astroparticle Physics, 2016Co-Authors: R F L Holanda, Susana J Landau, J S Alcaniz, V C BustiAbstract:We propose a new method to probe a possible time evolution of the fine structure constant α from X-ray and Sunyaev-Zel'dovich measurements of the gas mass fraction (fgas) in galaxy clusters. Taking into account a direct Relation between variations of α and violations of the distance-Duality Relation, we discuss constraints on α for a class of dilaton runaway models. Although not yet competitive with bounds from high-z quasar absorption systems, our constraints, considering a sample of 29 measurements of fgas, in the redshift interval 0.14 < z < 0.89, provide an independent estimate of α variation at low and intermediate redshifts. Furthermore, current and planned surveys will provide a larger amount of data and thus allow to improve the limits on α variation obtained in the present analysis.
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constraints on the hubble parameter from galaxy clusters and the validity of the cosmic distance Duality Relation
International Journal of Modern Physics D, 2012Co-Authors: R F L HolandaAbstract:Constraints on the Hubble parameter, H0, via X-ray surface brightness and Sunyaev–Zel'dovich effect (SZE) observations of the galaxy clusters depend on the validity of the cosmic distance Duality Relation (DD Relation), η = DL(z)(1+z)-2/DA(z) = 1, where DL and DA are the luminosity distance and angular diameter distance (ADD), respectively. In this work, we argue that if the DD Relation does not hold, the X-ray plus SZE technique furnishes a . We use 25 ADD of galaxy clusters to obtain simultaneous constraints on H0 and possible violation of the DD Relation in a flat ΛCDM model. Such a violation is parametrized by two functions: η(z) = 1 + η0z and η(z) = 1 + η0z/(1+z), where η0 is a constant parameter quantifying possible departures from the strict validity. Finally, by marginalizing on the η0 in both parametrizations, we obtain constraints on H0 regardless of the validity of the DD Relation. For the linear and nonlinear η(z) functions, we obtain km/s/Mpc and km/s/Mpc, respectively (without systematic errors). Our results support recent H0 measurements by using X-ray and SZE observations of galaxy clusters which have taken the distance Duality as valid.
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constraints on the hubble parameter from galaxy clusters and the validity of the cosmic distance Duality Relation
arXiv: Cosmology and Nongalactic Astrophysics, 2012Co-Authors: R F L HolandaAbstract:Constraints on the Hubble parameter, $H_0$, via X-ray surface brightness and Sunyaev-Zel'dovich effect (SZE) observations of the galaxy clusters depend on the validity of the cosmic distance Duality Relation (DD Relation), $\eta= D_{L}(z)(1+z)^{-2}/D_{A}(z) = 1$, where $D_L$ and $D_A$ are the luminosity distance and angular diameter distance (ADD), respectively. In this work, we argue that if the DD Relation does not hold the X-ray plus SZE technique furnishes a $H^{*}_{0}=H_{0}/\eta^{2}$. We use 25 ADD of galaxy clusters to obtain simultaneous constraints on $H_{0}$ and possible violation of the DD Relation in a flat $\Lambda$CDM model. Such a violation is parametrized by two functions: $\eta(z) = 1 + \eta_{0}z$ and $\eta(z) = 1 + \eta_{0}z/(1+z)$, where $\eta_0$ is a constant parameter quantifying possible departures from the strict validity. Finally, by marginalizing on the $\eta_{0}$ in both parameterizations, we obtain constraints on $H_0$ regardless of the validity of the DD Relation. For the linear and non linear $\eta(z)$ functions, we obtain $H_{0}= 75^{+ 7}_{-7}$ km/s/Mpc and $H_{0}= 75^{+ 10}_{-7}$ km/s/Mpc, respectively (without systematic erros). Our results support recent $H_{0}$ measurements by using X-ray and SZE observations of galaxy clusters which have taken the distance Duality as valid.
Holanda R. F. L. - One of the best experts on this subject based on the ideXlab platform.
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On the cosmic distance Duality Relation and the strong gravitational lens power law density profile
2021Co-Authors: Lima F. S., Holanda R. F. L., Pereira S. H., Da Silva W. J. C.Abstract:Many new strong gravitational lensing (SGL) systems have been discovered in the last two decades with the advent of powerful new space and ground-based telescopes. The effect of the lens mass model (usually the power-law mass model) on cosmological parameters constraints has been performed recently in literature. In this paper, by using SGL systems and Supernovae type Ia observations, we explore if the power-law mass density profile ($\rho \propto r^{-\gamma}$) is consistent with the cosmic distance Duality Relation (CDDR), $D_L(1+z)^{-2}/D_A=\eta(z)=1$, by considering different lens mass intervals. { It has been obtained that the verification of the CDDR validity is significantly dependent on lens mass interval considered: the sub-sample with $\sigma_{ap} \geq 300$ km/s (where $\sigma_{ap}$ is the lens apparent stellar velocity dispersion) is in full agreement with the CDDR validity, the sub-sample with intermediate $\sigma_{ap}$ values ($200 \leq \sigma_{ap} < 300)$ km/s is marginally consistent with $\eta=1$ and, finally, the sub-sample with low $\sigma_{ap}$ values ($\sigma_{ap} < 200$ km/s) ruled out the CDDR validity with high statistical confidence. Therefore, if one takes the CDDR as guarantee, our results suggest that using a single density profile is not suitable to describe lens with low $\sigma_{ap}$ values and it is only an approximate description to lenses with intermediate mass interval. }Comment: 8 pages, 4 figures, I table, Accepted for publication in the JCA
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Cosmological insights on the strong gravitational lens power law density profile
2021Co-Authors: Lima F. S., Holanda R. F. L., Pereira S. H., Da Silva W. J. C.Abstract:Many new strong gravitational lensing (SGL) systems have been discovered in the last two decades with the advent of powerful new space and ground-based telescopes. The effect of the lens mass model (usually the power-law mass model) on cosmological parameters constraints has been performed recently in literature. In this paper, by using SGL systems and Supernovae type Ia observations, we explore if the power-law mass density profile is consistent with the cosmic distance Duality Relation (CDDR), $D_L(1+z)^{-2}/D_A=\eta(z)=1$, by considering different lens mass intervals. It has been obtained that the verification of the CDDR validity is significantly dependent on lens mass interval considered: the sub-sample with $\sigma_{ap} \geq 300$ km/s (where $\sigma_{ap}$ is the lens apparent stellar velocity dispersion) is in full agreement with the CDDR validity, the sub-sample with intermediate $\sigma_{ap}$ values ($200 \leq \sigma_{ap} < 300)$ km/s is marginally consistent with $\eta=1$ and, finally, the sub-sample with low $\sigma_{ap}$ values ($\sigma_{ap} < 200$ km/s) ruled out the CDDR validity with high statistical confidence
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Strong lensing systems and galaxy cluster observations as probe to the cosmic distance Duality Relation
2021Co-Authors: Holanda R. F. L., Lima F. S., Rana Akshay, Jain DeepakAbstract:In this paper, we use large scale structure observations to test the cosmic distance Duality Relation (CDDR), $D_{\rm L}(1+z)^{-2}/D_{\rm A}=\eta=1 $, with $D_{\rm L}$ and $D_{\rm A}$, being the luminosity and angular diameter distances, respectively. In order to perform the test, the following data set are considered: strong lensing systems and galaxy cluster measurements (gas mass fractions). No specific cosmological model is adopted, only a flat universe is assumed. By considering two $\eta(z)$ parametrizations, we obtained the validity of the CDDR within $1.5\sigma$ which is in full agreement with other recent tests involving cosmological data. It is worth to comment that our results are independent of the baryon budget of galaxy clusters.Comment: 6 pages, two figs, one tabl
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Galaxy clusters, cosmic chronometers and the Einstein equivalence principle
'IOP Publishing', 2021Co-Authors: Mendonça I. E. C. R., Holanda R. F. L., Bora Kamal, Desai ShantanuAbstract:The Einstein equivalence principle in the electromagnetic sector can be violated in modifications of gravity theory generated by a multiplicative coupling of a scalar field to the electromagnetic Lagrangian. In such theories, deviations of the standard result for the cosmic distance Duality Relation, and a variation of the fine structure constant are expected and are unequivocally intertwined. In this paper, we search for these possible cosmological signatures by using galaxy cluster gas mass fraction measurements and cosmic chronometers. No significant departure from general relativity is found regardless of our assumptions about cosmic curvature or a possible depletion factor evolution in cluster measurements.Comment: 11 pages, 4 figures, I table, Accepted Version for Publication in JCA
Da Silva W. J. C. - One of the best experts on this subject based on the ideXlab platform.
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On the cosmic distance Duality Relation and the strong gravitational lens power law density profile
2021Co-Authors: Lima F. S., Holanda R. F. L., Pereira S. H., Da Silva W. J. C.Abstract:Many new strong gravitational lensing (SGL) systems have been discovered in the last two decades with the advent of powerful new space and ground-based telescopes. The effect of the lens mass model (usually the power-law mass model) on cosmological parameters constraints has been performed recently in literature. In this paper, by using SGL systems and Supernovae type Ia observations, we explore if the power-law mass density profile ($\rho \propto r^{-\gamma}$) is consistent with the cosmic distance Duality Relation (CDDR), $D_L(1+z)^{-2}/D_A=\eta(z)=1$, by considering different lens mass intervals. { It has been obtained that the verification of the CDDR validity is significantly dependent on lens mass interval considered: the sub-sample with $\sigma_{ap} \geq 300$ km/s (where $\sigma_{ap}$ is the lens apparent stellar velocity dispersion) is in full agreement with the CDDR validity, the sub-sample with intermediate $\sigma_{ap}$ values ($200 \leq \sigma_{ap} < 300)$ km/s is marginally consistent with $\eta=1$ and, finally, the sub-sample with low $\sigma_{ap}$ values ($\sigma_{ap} < 200$ km/s) ruled out the CDDR validity with high statistical confidence. Therefore, if one takes the CDDR as guarantee, our results suggest that using a single density profile is not suitable to describe lens with low $\sigma_{ap}$ values and it is only an approximate description to lenses with intermediate mass interval. }Comment: 8 pages, 4 figures, I table, Accepted for publication in the JCA
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Cosmological insights on the strong gravitational lens power law density profile
2021Co-Authors: Lima F. S., Holanda R. F. L., Pereira S. H., Da Silva W. J. C.Abstract:Many new strong gravitational lensing (SGL) systems have been discovered in the last two decades with the advent of powerful new space and ground-based telescopes. The effect of the lens mass model (usually the power-law mass model) on cosmological parameters constraints has been performed recently in literature. In this paper, by using SGL systems and Supernovae type Ia observations, we explore if the power-law mass density profile is consistent with the cosmic distance Duality Relation (CDDR), $D_L(1+z)^{-2}/D_A=\eta(z)=1$, by considering different lens mass intervals. It has been obtained that the verification of the CDDR validity is significantly dependent on lens mass interval considered: the sub-sample with $\sigma_{ap} \geq 300$ km/s (where $\sigma_{ap}$ is the lens apparent stellar velocity dispersion) is in full agreement with the CDDR validity, the sub-sample with intermediate $\sigma_{ap}$ values ($200 \leq \sigma_{ap} < 300)$ km/s is marginally consistent with $\eta=1$ and, finally, the sub-sample with low $\sigma_{ap}$ values ($\sigma_{ap} < 200$ km/s) ruled out the CDDR validity with high statistical confidence
Lima F. S. - One of the best experts on this subject based on the ideXlab platform.
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On the cosmic distance Duality Relation and the strong gravitational lens power law density profile
2021Co-Authors: Lima F. S., Holanda R. F. L., Pereira S. H., Da Silva W. J. C.Abstract:Many new strong gravitational lensing (SGL) systems have been discovered in the last two decades with the advent of powerful new space and ground-based telescopes. The effect of the lens mass model (usually the power-law mass model) on cosmological parameters constraints has been performed recently in literature. In this paper, by using SGL systems and Supernovae type Ia observations, we explore if the power-law mass density profile ($\rho \propto r^{-\gamma}$) is consistent with the cosmic distance Duality Relation (CDDR), $D_L(1+z)^{-2}/D_A=\eta(z)=1$, by considering different lens mass intervals. { It has been obtained that the verification of the CDDR validity is significantly dependent on lens mass interval considered: the sub-sample with $\sigma_{ap} \geq 300$ km/s (where $\sigma_{ap}$ is the lens apparent stellar velocity dispersion) is in full agreement with the CDDR validity, the sub-sample with intermediate $\sigma_{ap}$ values ($200 \leq \sigma_{ap} < 300)$ km/s is marginally consistent with $\eta=1$ and, finally, the sub-sample with low $\sigma_{ap}$ values ($\sigma_{ap} < 200$ km/s) ruled out the CDDR validity with high statistical confidence. Therefore, if one takes the CDDR as guarantee, our results suggest that using a single density profile is not suitable to describe lens with low $\sigma_{ap}$ values and it is only an approximate description to lenses with intermediate mass interval. }Comment: 8 pages, 4 figures, I table, Accepted for publication in the JCA
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Cosmological insights on the strong gravitational lens power law density profile
2021Co-Authors: Lima F. S., Holanda R. F. L., Pereira S. H., Da Silva W. J. C.Abstract:Many new strong gravitational lensing (SGL) systems have been discovered in the last two decades with the advent of powerful new space and ground-based telescopes. The effect of the lens mass model (usually the power-law mass model) on cosmological parameters constraints has been performed recently in literature. In this paper, by using SGL systems and Supernovae type Ia observations, we explore if the power-law mass density profile is consistent with the cosmic distance Duality Relation (CDDR), $D_L(1+z)^{-2}/D_A=\eta(z)=1$, by considering different lens mass intervals. It has been obtained that the verification of the CDDR validity is significantly dependent on lens mass interval considered: the sub-sample with $\sigma_{ap} \geq 300$ km/s (where $\sigma_{ap}$ is the lens apparent stellar velocity dispersion) is in full agreement with the CDDR validity, the sub-sample with intermediate $\sigma_{ap}$ values ($200 \leq \sigma_{ap} < 300)$ km/s is marginally consistent with $\eta=1$ and, finally, the sub-sample with low $\sigma_{ap}$ values ($\sigma_{ap} < 200$ km/s) ruled out the CDDR validity with high statistical confidence
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Strong lensing systems and galaxy cluster observations as probe to the cosmic distance Duality Relation
2021Co-Authors: Holanda R. F. L., Lima F. S., Rana Akshay, Jain DeepakAbstract:In this paper, we use large scale structure observations to test the cosmic distance Duality Relation (CDDR), $D_{\rm L}(1+z)^{-2}/D_{\rm A}=\eta=1 $, with $D_{\rm L}$ and $D_{\rm A}$, being the luminosity and angular diameter distances, respectively. In order to perform the test, the following data set are considered: strong lensing systems and galaxy cluster measurements (gas mass fractions). No specific cosmological model is adopted, only a flat universe is assumed. By considering two $\eta(z)$ parametrizations, we obtained the validity of the CDDR within $1.5\sigma$ which is in full agreement with other recent tests involving cosmological data. It is worth to comment that our results are independent of the baryon budget of galaxy clusters.Comment: 6 pages, two figs, one tabl
Tadashi Takayanagi - One of the best experts on this subject based on the ideXlab platform.
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surface state correspondence as a generalized holography
Progress of Theoretical and Experimental Physics, 2015Co-Authors: Masamichi Miyaji, Tadashi TakayanagiAbstract:We propose a new Duality Relation between codimension two space-like surfaces in gravitational theories and quantum states in dual Hilbert spaces. This surface/state correspondence largely generalizes the idea of holography such that we do not need to rely on any existence of boundaries in gravitational spacetimes. The present idea is motivated by the recent interpretation of AdS/CFT in terms of the tensor networks so called MERA. Moreover, we study this correspondence from the viewpoint of entanglement entropy and information metric. The Cramer-Rao bound in quantum estimation theory implies that the quantum fluctuations of radial coordinate of the AdS is highly suppressed in the large N limit.
