A5076117050- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Galaxies: Formation, Evolution, Phenomena
- Noncommutative and Quantum Gravity Theories
- Relativity and Gravitational Theory
- Astronomy and Astrophysical Research
- Stochastic processes and financial applications
- Quantum Electrodynamics and Casimir Effect
- Dark Matter and Cosmic Phenomena
- Experimental and Theoretical Physics Studies
- 3D Printing in Biomedical Research
- Earth Systems and Cosmic Evolution
- Gas Dynamics and Kinetic Theory
- Cell Adhesion Molecules Research
- Computational Physics and Python Applications
- Advanced Algebra and Logic
- Cellular Mechanics and Interactions
- Quantum Chromodynamics and Particle Interactions
- Advanced Thermodynamics and Statistical Mechanics
Universitat de Barcelona
2019-2023
Istituto Nazionale di Fisica Nucleare
2021
Institute for Bioengineering of Catalonia
2017
We analyze Brans-Dicke gravity with a cosmological constant, $\Lambda$, and cold dark matter (BD-$\Lambda$CDM for short) in the light of latest observations on distant supernovae, Hubble rate measurements at different redshifts, baryonic acoustic oscillations, large scale structure formation data, gravitational weak-lensing cosmic microwave background under full Planck 2015 CMB likelihood. Our analysis includes both perturbations equations. find that BD-$\Lambda$CDM is observationally...
The cosmological term, $\Lambda$, was introduced $104$ years ago by Einstein in his gravitational field equations. Whether $\Lambda$ is a rigid quantity or dynamical variable cosmology has been matter of debate for many years, especially after the introduction general notion dark energy (DE). associated to vacuum density, $\rho_{\rm vac}$, and one may expect that it evolves slowly with expansion. Herein we present devoted study testing this possibility using promising class running models...
The renormalization of the vacuum energy in quantum field theory (QFT) is usually plagued with theoretical conundrums related not only procedure itself, but also fact that final result leads to very large (finite) contributions incompatible measured value $\Lambda$ cosmology. Herein, we compute zero-point (ZPE) for a nonminimally coupled (massive) scalar FLRW spacetime using off-shell adiabatic technique employed previous work. general yields smooth function $\rho_{\rm vac}(H)$ made out...
Abstract Recent studies of quantum field theory in FLRW spacetime suggest that the cause speeding up universe is running vacuum (RV), see Moreno-Pulido and Solà Peracaula (Eur Phys J C 82(6):551, 2022; Eur 80(8):692, 2020). Appropriate renormalization energy-momentum tensor shows energy density a smooth function Hubble rate its derivatives: $$\rho _\textrm{vac}=\rho _\textrm{vac}(H, {\dot{H}},\ddot{H},\ldots )$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub>...
A substantial body of phenomenological and theoretical work over the last few years strengthens possibility that vacuum energy density (VED) universe is dynamical, in particular it adopts ‘running model’ (RVM) form, which VED evolves mildly as δρvac(H)∼νeffmPl2OH2, where H Hubble rate νeff a (small) free parameter. This dynamical scenario grounded on recent studies quantum field theory (QFT) curved spacetime also string theory. It turns out what we call ‘cosmological constant’, Λ, no longer...
Abstract Phenomenological work in the last few years has provided significant support to idea that vacuum energy density (VED) is a running quantity with cosmological evolution and this helps alleviate tensions afflicting $$\Lambda $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>Λ</mml:mi> </mml:math> CDM. On theoretical side, recent devoted studies have shown properly renormalized $$\rho _{\textrm{vac}}$$ <mml:msub> <mml:mi>ρ</mml:mi> <mml:mtext>vac</mml:mtext>...
We present a full-fledged analysis of Brans-Dicke cosmology with cosmological constant and cold dark matter (BD-$\Lambda$CDM for short). extend the scenarios where current value BD-field is restricted by local astrophysical domain to that fixed only observations, which should be more natural in view possible existence screening mechanims. Our includes both background perturbations equations different gauges. find BD-$\Lambda$CDM favored overall data as compared concordance GR-$\Lambda$CDM...
Abstract The $$\Lambda $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Λ</mml:mi></mml:math> -term in Einstein’s equations is a fundamental building block of the ‘concordance’ CDM model cosmology. Even though not free problems, they have been circumvented by any alternative dark energy proposal either. Here we stick to -term, but contend that it can be ‘running quantity’ quantum field theory (QFT) curved space time. A plethora phenomenological works shown this option...
Phenomenological work in the last few years has provided significant support to idea that vacuum energy density (VED) is a running quantity with cosmological evolution and this helps alleviate tensions afflicting $Λ$CDM. On theoretical side, recent devoted studies have shown properly renormalized $ρ_{\rm vac}$ QFT FLRW spacetime adopts "running model" (RVM) form. While three previous by two of us (CMP JSP) such computations focused solely on scalar fields non-minimally coupled gravity,...
A substantial body of phenomenological and theoretical work over the last few years strengthens possibility that vacuum energy density (VED) universe is dynamical, in particular it adopts `running model&#039; (RVM) form, which VED evolves mildly as $\delta \rho_{\rm vac}(H)\sim \nu_{\rm eff} m_{\rm Pl}^2{\cal O}\left(H^2\right)$, where $H$ Hubble rate $\nu_{\rm eff}$ a (small) free parameter. This dynamical scenario grounded on recent studies quantum field theory (QFT) curved spacetime...
A substantial body of phenomenological and theoretical work over the last few years strengthens possibility that vacuum energy density (VED) universe is dynamical, in particular it adopts `running model' (RVM) form, which VED evolves mildly as $δρ_{\rm vac}(H)\sim ν_{\rm eff} m_{\rm Pl}^2{\cal O}\left(H^2\right)$, where $H$ Hubble rate $ν_{\rm eff}$ a (small) free parameter. This dynamical scenario grounded on recent studies quantum field theory (QFT) curved spacetime also string theory. It...
The cosmological constant term (CC), $\Lambda$, is a pivotal ingredient in the standard model of cosmology or $\Lambda$CDM, but it rigid quantity for entire cosmic history. This unnatural and inconsistent. Different theoretical phenomenological conundrums suggest that $\Lambda$CDM necessitates further underpinning to cope with modern observations. An interesting approach framework `running vacuum model' (RVM). It endows $\Lambda$ dynamics within fundamental since based on QFT. In RVM, energy...
The cosmological constant term, $Λ$, in Einstein's equations has been for three decades a building block of the concordance or standard $Λ$CDM model cosmology. Although latter is not free fundamental problems, it provides good phenomenological description overall observations. However, an interesting improvement such and also change theoretical status $Λ$-term occurs upon realizing that vacuum energy density, $ρ_{\textrm{vac}}$, actually "running quantity" quantum field theory curved...
We present an analysis of the Brans-Dicke cosmological model with a constant and cold dark matter (BD-$Λ$CDM). find that BD-$Λ$CDM is favored by overall data (SNIa+BAO+$H(z)$+LSS+CMB) when it compared standard cosmology. The can be viewed from GR perspective as Running Vacuum Model (RVM) time evolving vacuum energy density. Due to this fact also its effective gravitational coupling, alleviate $σ_8$ $H_0$ tensions at time. results for different types RVM's they are tested in light we show...
Recent studies of quantum field theory in FLRW spacetime suggest that the cause speeding up universe is running vacuum (RV). Appropriate renormalization energy-momentum tensor shows energy density a smooth function Hubble rate and its derivatives: $ρ_{\rm vac}=ρ_{\rm vac}(H, \dot{H},\ddot{H},...)$. This because QFT scaling vac}$ with point turns into cosmic evolution $H$. As result, any two nearby points expansion during standard epoch are smoothly related through $δρ_{\rm vac}\sim {\cal...
The $\Lambda$CDM cosmology, which includes a Cosmological Constant (CC), has been the dominant paradigm for past 25 years. However, appearance of tensions in different cosmological parameters and persistence traditional theoretical problems associated with CC challenge validity viability model, leading to search new physics. Recent studies vacuum energy quantum field theory FLRW spacetime predict that this physics may be related slow running density Hubble function. can described by...
In this dissertation, the nature of Dark Energy (DE) is examined from both theoretical and phenomenological perspectives. The possibility DE being a dynamic quantity in quantum field theory (QFT) curved spacetime studied. primary aim to go beyond usual approach that relies on ad hoc fields instead treat as vacuum under appropriate QFT renormalization. Specifically, behavior could arise fluctuations Universe, evolving alongside background expansion. Thus, evolution energy density can be...