Browsing by Author "Laporte, Cristobal"

Now showing 1 - 5 of 5
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    Can scale-dependent cosmology alleviate the H0 tension?
    (2021) Alvarez, Pedro D.; Koch, Benjamin; Laporte, Cristobal; Rincon, Angel
    Scale-dependence is a common feature to all effective models of quantum gravity. In this paper, a cosmological model based on the scale-dependent scenario of gravity is presented. It is argued that such models, where the scale-dependence appears as a correction to the classical Lambda CDM evolution, have the potential of addressing the tensions between early and late time measurements of H-0. After defining criteria to parametrize this tension, we perform a numerical scan over the parameter space of the scale-dependent model, subject to these criteria. In this analysis, it is found that, indeed, the tension can be released.
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    Gauge boson masses from the scale-dependent interplay between the gravitational and the electroweak sector
    (2022) Laporte, Cristobal; Koch, Benjamin; Canales Contreras, Felipe Andrés; Rincon, Angel
    In this paper we explore the interplay of scale dependence arising in the electroweak and the gravitational sector. Using the method of variational parameter setting leads naturally to spontaneous symmetry breaking and thus to electroweak gauge boson masses. We explore the phenomenological prospect of this model and the mapping to the program asymptotic safety.
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    Observational constraints on scale-dependent cosmology
    (2024) Alvarez, Pedro D.; Koch, Benjamin; Laporte, Cristobal; Rincon, Angel
    This paper examines a cosmological model of scale-dependent gravity. The gravitational action is taken to be the Einstein-Hilbert term supplemented with a cosmological constant, where the couplings, G k and A k , run with the energy scale k. Also, notice that, by construction, our formalism recovers general relativity when in the limit of constant Newton's coupling. Two sub-models based on the scale-dependent cosmological model are confronted with recent observational data from: (i) the Hubble parameter H ( z ) , (ii) distance modulus mu ( z ) and (iii) baryon acoustic scale evolution as functions of redshift (BAO). The viability of the model is discussed, obtaining the best-fit parameters and the maximum likelihood contours for these observables. Finally, a joint analysis is performed for H ( z )+ mu ( z )+ BAO.
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    Statefinder analysis of scale-dependent cosmology
    (2022) Alvarez, Pedro D.; Koch, Benjamin; Laporte, Cristobal; Canales, Felipe; Rincon, Angel
    We study the statefinder parameters of a cosmological model based on scale -dependent gravity. The effective Einstein field equations come from an average effective action. From the dynamical system, we derive analytical expressions that improve the con-vergence of the numerical solutions. We determine the statefinder parameters for moderate redshift and compare them with well-known alternatives to ACDM.
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    The effects of running gravitational coupling on three dimensional black holes
    (2023) Rincón, Ángel; Koch, Benjamin; Laporte, Cristobal; Canales, Felipe; Cruz, Norman
    In the present work, we investigate the consequences of running gravitational coupling on the properties of the three-dimensional BTZ black hole. We take as starting point the functional form of gravitational coupling obtained in the context of asymptotic safe gravity theory. By using the standard scale setting relation where $$k\sim \xi /r^n$$ k ∼ ξ / r n , we compute the solution of the Einstein field equations. We get and analyze the horizon and the thermodynamic properties of this new class of black hole solutions. The impact of the scale-dependent parameter $$\xi $$ ξ on the cosmological “constant” and metric functions are briefly discussed. We find that the null energy condition is also violated in this setup when scale-dependent gravity and Newton’s coupling (coming from the asymptotic safety scenario of gravity) are simultaneously taken into account.