arXiv subjects

Celia Escamilla-Rivera

Publications and source records attributed to Celia Escamilla-Rivera.

At least 19 recordsLinked to original sources

arXiv2026

Scalar perturbations on the normal and self-accelerating branch of a DGP brane and $σ_8$

In this work we constrain the value of $σ_8$ for the normal and self-accelerating branch of a DGP brane embedded in a five-dimensional Minkowski space-time. For that purpose we first constrain the model parameters $H_0$, $Ω_{m0}$, $Ω_{r0}$ and $M$ by means of the Pantheon+ catalog and a mock catalog of gravitational waves. Then, we solve numerically the equation for dark matter scalar perturbations using the dynamical scaling solution for the master equation and assuming that $p=4$ for the matter dominated era. Finally, we found that the evolution of matter density perturbations in both branches is different from the $Λ$CDM model and that the value of $σ_8=0.774\pm0.027$ for the normal branch and $σ_8=0.913\pm0.032$ for the self-accelerating branch.

gr-qc↗

arXiv2024

$f(T)$ gravity after DESI Baryon Acoustic Oscillation and DES Supernovae 2024 data

In this work, we investigate new constraints on $f(T)$ gravity using the recent Baryon Acoustic Oscillation (BAO) data released by the Dark Energy Spectroscopic Instrument (DESI) and the Type Ia supernovae (SNIa) catalog from the full 5-years of the Dark Energy Survey Supernova Program (DES-SN5YR). The $f(T)$ cosmological models considered are characterised by power law late-time accelerated expansion. Our results show that the combination DESI BAO +$r_d$ CMB Planck suggests a Bayesian preference for late-time $f(T)$ cosmological models over $Λ$CDM, obtaining a value of $H_0= 68.3^{+3.0}_{-3.5}$[km/s/Mpc] in agreement with SH0ES collaboration, however, due to a bigger uncertainty.

astro-ph.CO↗

arXiv2024

Testing $f(T)$ cosmologies with HII Hubble diagram and CMB distance priors

In this work, we present independent determinations of cosmological parameters and new constraints on $f(T)$ cosmologies, employing two new catalogs related to HII galaxy Hubble and CMB distance priors, along with the local standard measurements, SNIa, $H(z)$ measurements, growth rate data (RSD), and BAO baselines. We found that the marginalised best-fit C.L. $H_0$ and $σ_8$ parameters within these cosmologies can relax the current cosmological tensions using HIIG data. This produces a larger range of admissible values for the current Hubble constant, and when all baselines are considered, the uncertainty bands for $H_0$ and the matter density parameter reduce significantly.

astro-ph.CO↗

arXiv2024

Strengthening interacting agegraphic dark energy DGP constraints with local measurements and multimessenger forecastings

An explanation of the nature of dark energy has been treated in extra dimensions within the scheme of string theory. One of the most successful models is inspired by the Dvali-Gabadadze-Porrati (DGP) model, in which the universe is a 4-dimensional brane embedded in a 5-dimensional Minkowski space-time. In this landscape, the study of the evolution of the normal branch has led us to different kinds of dark energy, where the most simple case is the cosmological constant $Λ$. Moreover, other viable cosmological solutions are related to agegraphic dark energy, which allows a late cosmic acceleration within an interacting mechanism. To explore the viability of these solutions and possible gravitational leakage, in this paper, we present constraints on such models using recent standard sirens forecasting in addition to local observables such as Pantheon (SNIa), $H(z)$ measurements, baryonic acoustic oscillations (BAO). Our results show that the value associated with the species of quantum fields $n$ in these models is strongly restricted for supernovae observations to $n=20$, and for GW standard sirens mock data prefers a value of $n=1$.

gr-qc↗

arXiv2024

Phantom scalar field cosmologies constrained by early cosmic measurements

In this work, we explore new constraints on phantom scalar field cosmologies with a scalar field employing early times catalogues related to CMB measurements, along with the local standard observables, like Supernovae Type Ia (SNIa), $H(z)$ measurements (Cosmic Clocks), and Baryon Acoustic Oscillations (BAO) baselines. In particular, we studied a tracker phantom field with hyperbolic polar coordinates that have been proposed in the literature. The main goal is to obtain precise cosmological constraints for $H_0$ and $σ_8$, in comparison to other constructions that present tension in early cosmological parameters. Our results show that phantom scalar field cosmologies have a reduced statistical tension on $H_0$ that it is less than 3$σ$ using model-independent CMB catalogues as SPT-3G+WMAP9 and ACTPol DR-4+WMAP9 baselines. This suggests these models using a different phantom potential might address the Hubble constant problem and reduce the systematics involved.

gr-qc↗

arXiv2024

Non-fluid like Boltzmann code architecture for early times f(T) cosmologies

There have been several works that have studied scalar cosmological perturbations in $f(T)$ teleparallel gravity theories to understand early cosmic times dynamics. In this direction, the perturbations presented have been performed by considering $f(T)$ extensions as an effective fluid-like scheme, where the equation-of-state contains extra terms due to the torsion. In this work, we discuss introducing a non-fluid-like approach as a direct consequence of $f(T)$ extensions, particularly for $f(T)$ power law model scenarios. This approach will be compared using CMB constraints data from Planck 2018 and SDSS catalogs, showing a change in about 17% in $C_{l}$ at $l< 10^{1}$ from the ones reported in the literature as a fluid-like approach, which will bring significant changes in the analysis on cosmological tensions at early cosmic times.

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arXiv2024

Constraining dark energy cosmologies with spatial curvature using Supernovae JWST forecasting

Recent cosmological tensions, in particular, to infer the local value of the Hubble constant $H_0$, have developed new independent techniques to constrain cosmological parameters in several cosmologies. Moreover, even when the concordance Cosmological Constant Cold Dark Matter ($Λ$CDM) model has been well constrained with local observables, its physics has shown deviations from a flat background. Therefore, to explore a possible deviation from a flat $Λ$CDM model that could explain the $H_0$ value in tension with other techniques, in this paper we study new cosmological constraints in spatial curvature dark energy models. Additionally, to standard current Supernovae Type Ia (SNIa) catalogs, we extend the empirical distance ladder method through an SNIa sample using the capabilities of the James Webb Space Telescope (JWST) to forecast SNIa up to $z \sim 6$, with information on the star formation rates at high redshift. Furthermore, we found that our constraints provide an improvement in the statistics associated with $Ω_{m}$ when combining SNIa Pantheon and SNIa Pantheon+ catalogs with JW forecasting data.

astro-ph.CO↗

arXiv2024

Growth of structures using redshift space distortion in $f(T)$ Cosmology

Cosmology faces a pressing challenge with the Hubble constant ($H_0$) tension, where the locally measured rate of the Universe's expansion does not align with predictions from the cosmic microwave background (CMB) calibrated with $Λ$CDM model. Simultaneously, there is a growing tension involving the weighted amplitude of matter fluctuations, known as $S_{8,0}$ tension. Resolving both tensions within one framework would boost confidence in any one particular model. In this work, we analyse constraints in $f(T)$ gravity, a framework that shows promise in shedding light on cosmic evolution. We thoroughly examine prominent $f(T)$ gravity models using a combination of data sources, including Pantheon+ (SN), cosmic chronometers (CC), baryonic acoustic oscillations (BAO) and redshift space distortion (RSD) data. We use these models to derive a spectrum of $H_0$ and $S_{8,0}$ values, aiming to gauge their ability to provide insights into, and potentially address, the challenges posed by the $H_0$ and $S_{8,0}$ tensions.

astro-ph.CO↗

arXiv2023

$f(T)$ cosmology in the regime of quasar observations

The open problems related to cosmological tensions in current times have opened new paths to study new probes to constrain cosmological parameters in standard and extended cosmologies, in particular, to determine at a local level the value of the Hubble constant $H_0$, through independent techniques. However, while standard Cosmological Constant Cold Dark Matter ($Λ$CDM) model has been well constrained and parts of extended cosmology have been intensively studied, the physics behind them aspects restrains our possibilities of selecting the best cosmological model that can show a significant difference from the first model. Therefore, to explore a possible deviation from a such model that can explain the current discrepancy on the $H_0$ value, in this work we consider adding the current local observables, e.g. Supernovae Type Ia (SNIa), $H(z)$ measurements, and Baryon Acoustic Observations (BAO) combined with two new calibrated Quasars (QSO) datasets using ultraviolet, x-ray and optical plane techniques. While these can be identified as part of the high-redshift standard candle objects, the main characteristics of these are based on fluxes distributions calibrated up to $z \sim 7 $. We consider five $H_0$ prior scenarios to develop these calibrations. Furthermore, we found that our estimations provide the possibility to relax the $H_0$ tension at 2$σ$ using a QSO ultraviolet sample in combination with late measurements showing higher values of $H_0$. Our results can be an initial start for more serious treatments in the quasars physics from ultraviolet, x-ray, and optical plane techniques behind the local observations as cosmological probes to relax the cosmological tensions problems.

astro-ph.CO↗

arXiv2023

Production of Primordial Gravitational Waves in Teleparallel Gravity

We study the production of primordial gravitational waves in the context of extended teleparallel gravity models and compare them with those of general relativity. Teleparallel gravity has been widely studied in the context of the late universe but not much in the early universe. Two sources of primordial gravitational waves are considered, vacuum fluctuations and tensor anisotropies within two inflation-compatible backgrounds: a perfect de Sitter and a quasi de Sitter background. We find that in the vacuum case with a perfect de Sitter background, the gravitational waves propagation equation is the same as that of general relativity, however, if the background is promoted to a quasi de Sitter background, the propagation equations are different resulting in an important difference on the tensor spectral index. When tensor anisotropies are included, we compute the most general solution for gravitational waves in terms of a retarded Green's function and analyze the contributions to the power spectrum from these anisotropies. Finally, we investigate the energy density of these gravitational waves.

gr-qc↗

arXiv2023

Constraints on $f(Q)$ logarithmic model using gravitational wave standard sirens

In this paper, we study the constraints on the $f(Q)=Q/(8πG) - α\ln(Q/Q_0)$, symmetric teleparallel model using local measurements and gravitational wave mock standard sirens. Using observational local SNIa and BAO data and energy conditions, the logarithmic $f(Q)$ model is capable of explaining the cosmic late-time acceleration by geometrical means. This result suggests that the logarithmic symmetric teleparallel model could be a candidate to solve the cosmological constant problem. In the case of the simulated standard siren data, by using the performance of the future ET and LISA detectors, we expect to be able to measure the current Hubble constant $H_0$, and the matter content $Ω_m$, with a precision better than 1\% and 6\%, respectively. Furthermore, we explore the predicted $f(Q)$ logarithmic model deviation from the standard GR using ET and LISA mock standard sirens. The ratio $d_L^{\text{gw}}(z)/d_L^{\text{em}}(z)$, which quantifies the deviation from GR gives us a significant deviation higher than 13\% at $z=1$, and it continues growing to reach a deviation higher than 18\% in its median value. Future standard siren data will be able to quantify the strength of the deviation from GR and hence whether a cosmology like the one implied by this $f(Q)$ model is feasible.

gr-qc↗

arXiv2023

Fab-Four cosmography to tackle the Hubble tension

In the context of the Fab-Four theory of gravity in a Friedmann-Lemaître-Robertson-Walker background, in this work we use the cosmography approach to study a particular self-tuning filter solution focused on a zero-curvature fixed point to study the $H_0$ tension. In this scheme, the equations restrict the universe's evolution to certain scenarios, including radiation-like expansion, matter-like expansion, and late-time acceleration. Furthermore, we build the cosmographic series of the Fab-Four theory to obtain the kinematic parameters as the Hubble constant $H_0$ and the deceleration parameter $q_0$ for all the scenarios mentioned. Finally, we compare our results to find that it is possible to alleviate the current discrepancy on $H_0$ by considering specific requirements on the free parameters of the Fab-Four theory through a self-tuning filter.

gr-qc↗

arXiv2023

On primordial gravitational waves in Teleparallel Gravity

Teleparallel Gravity is a gauge theory where gravity is a manifestation of the torsion of space-time and its success relies on being a possible solution to some problems of General Relativity. In this essay we introduce the construction of the theory by defining its geometrical setup, and how we can build it as a gauge theory of translations locally invariant under the Lorentz group. In this context, we will study the production of primordial gravitational waves and the observational implications when extended models are taken into account, particularly, we will notice how the tensor spectral index changes and produces a direct impact on the power spectrum from vacuum fluctuations and any source of tensor anisotropic stress in comparison to General Relativity.

gr-qc↗

arXiv2023

Chameleon perfect scalar field as a geometric correction in $f(R)$ gravity

In this work, we derive the analytical form for a $f(R)$ model that describes a perfect scalar field $ϕ$ by assuming the existence of a chameleon mechanism. Based on four statements, at the background and perturbative level, it is possible to relate the extra terms from this theory as a geometrical perfect fluid term, whose has been expressed as possible candidates to explain the nature of the dark sector, and possibly, in the case of a perfect scalar chameleon during inflation, satisfy the big bang nucleosynthesis (BBN) constraints until late times.

gr-qc↗

arXiv2023

Constraints on $f(T)$ Cosmology with Pantheon+

$f(T)$ cosmology has shown promise in explaining aspects of cosmic evolution. In this work, we analyze constraints on leading models of $f(T)$ gravity in the context of the recently released Pantheon+ data set, together with comparisons with previous releases. We also consider other late-time data sets including cosmic chronometers and baryonic acoustic oscillation data. Our main result is that we find that the different $f(T)$ models under investigation connect to a variety of Hubble constant, which may help alleviate the cosmic tension on this parameter.

gr-qc↗

arXiv2023

Comment on: "Questioning the $H_0$ tension via the look-back time"

Recently, it has been proposed that Hubble tension can be addressed in the $Λ$CDM model if the lookback time approach is considered on the redshift $z$ measured. From this interesting proposal, the lookback time evolution seems to match the observational values of the current Hubble parameter $H_0$ at any $z$. In this comment, we discuss that using a lookback time approach function $H_{0}^{(z)}$, does not address the $H_0$ tension issue completely. It has been studied that the growing tension among early-time and local measurements of $H_0$ are possible concealed sources of systematic error in observations or modifications (or extensions) to the standard $Λ$CDM model. Furthermore, we show that the age of the Universe is sensitive to both $Ω_m$ and $H_0$ in flat $Λ$CDM-like cosmological models.

gr-qc↗

arXiv2023

Teleparallel Gravity: From Theory to Cosmology

Teleparallel gravity has significantly increased in popularity in recent decades, bringing attention to Einstein's other theory of gravity. In this Review, we relate this form of geometry to the broader metric-affine approach to forming gravitational theories where we describe a systematic way of constructing consistent teleparallel theories that respect certain physical conditions such as local Lorentz invariance. We first use teleparallel gravity to formulate a teleparallel equivalent of general relativity which is dynamically equivalent to general relativity but which may have different behaviors for other scenarios, such as quantum gravity. After setting this foundation, we describe the plethora of modified teleparallel theories of gravity that have been proposed in the literature. In the second part of the Review, we first survey works in teleparallel astrophysics literature where we focus on the open questions in this regime of physics. We then discuss the cosmological consequences for the various formulations of teleparallel gravity. We do this at background level by exploring works using various approaches ranging from dynamical systems to Noether symmetries, and more. Naturally, we then discuss perturbation theory, firstly by giving a concise approach in which this can be applied in teleparallel gravity theories and then apply it to a number of important theories in the literature. Finally, we examine works in observational and precision cosmology across the plethora of proposal theories. This is done using some of the latest observations and is used to tackle cosmological tensions which may be alleviated in teleparallel cosmology. We also introduce a number of recent works in the application of machine learning to gravity, we do this through deep learning and Gaussian processes, together with discussions about other approaches in the literature.

gr-qc↗

arXiv2023

Exploring bulk viscous unified scenarios with Gravitational Waves Standard Sirens

We consider the unified bulk viscous scenarios and constrain them using the Cosmic Microwave Background observations from Planck 2018 and the Pantheon sample from Type Ia Supernovae. Then we generate the luminosity distance measurements from ${\cal O}(10^3)$ mock Gravitational Wave Standard Sirens (GWSS) events for the proposed Einstein Telescope. We then combine these mock luminosity distance measurements from the GWSS with the current cosmological probes in order to forecast how the mock GWSS data could be effective in constraining these bulk viscous scenarios. Our results show that a non-zero time dependent bulk viscosity in the universe sector is strongly preferred by the current cosmological probes and will possibly be confirmed at many standard deviations by the future GWSS measurements. We further mention that the addition of GWSS data can significantly reduce the uncertainties of the key cosmological parameters obtained from the usual cosmological probes employed in this work.

astro-ph.CO↗