Resumen:

The existence of supermassive black holes (SMBHs) of $10^9$ solar masses in quasars when the age of the universe was less than 700 Myr is an intriguing puzzle. How the seeds of these SMBHs have been formed and have grown so fast to become so large? I will briefly review recent models in the context of dark matter cosmologies where the seeds of the SMBHs at redshifts $z > 6$ are formed by direct collapse of dark matter haloes, before the formation of Pop III stars. Then I will review recent observations that suggest MBHs in primordial galaxies come first and grow faster than stellar populations. In this context, and based on observations in the local and distant Universe, I will conclude that jets from the rapidly growing seeds of the SMBHs in the early universe would have induced the formation of the first massive stars of Pop III.

Resumen:

Type Ia Supernovae (SNIa) are fundamental distance indicators for cosmology thanks to their nature as standardizable candles. In the next few years, the Rubin Observatory Legacy Survey of Space and Time (Rubin LSST) will provide a sample of millions of SNIa due to its large sky coverage and high cadence. Apart from the direct measurement of cosmological parameters with traditional methods of SNIa analysis, this sample can be used to measure the growth rate of structures in the universe through the study of peculiar velocities. These velocities are caused by the gravitational attraction of the large-scale structure of the universe: as galaxies (and their SN) tend to move towards denser regions, objects in the same region of the sky have correlated velocities. These correlations can be employed to study the intensity of the gravitational interaction on large scales. Current techniques rely on traditional three-dimensional statistical estimators for the data analysis. However, these estimators are inconvenient for application to Rubin LSST data, which will use angular power spectra to extract cosmological signals from galaxy overdensities and gravitational lensing. In this study, we will apply the Fisher information matrix methodology to the angular power spectrum of SNIa peculiar velocities. The main goal is to demonstrate the viability of using this estimator for the expected Rubin LSST data, comparing its constraints with those of traditional 3d estimators. We will investigate scenarios with velocities alone, and in combination with galaxy density and gravitational lensing observables (so-called "3x2pt" observables). We will explore the impact of different assumptions on the observational properties of the sample. This is a first step towards future measurements of cosmological parameters using a combination of Type Ia supernova peculiar velocities and 3x2pt cosmological estimators in the context of Rubin LSST.

Resumen:

The Hubble-Lemaître Law provides a satisfactory description of the universe's dynamics for low redshifts and reveals insights about its expansion rate. However, at higher redshift values, additional incorporation of the Friedmann equations within the framework of General Relativity is necessary. This project focuses on analyzing large-scale structures of the local universe, specifically at low redshifts, using Hubble-Lemaître diagrams. The goal is to understand the dynamics of universe expansion by studying the Hubble constant independently of specific cosmological models. By utilizing the ALFALFA catalog, the Hubble constant is measured, considering potential systematic effects and using velocity reference frames that minimize peculiar velocity influences. Transformations of frames of reference, e.g. Local Group and CMB frames, and statistical methods were employed to achieve a more accurate determination of the Hubble constant. Within 1 sigma confidence level, the values for the Hubble constant are equivalent between the two hemispheres. The findings of this work, which contributed to the publication of an article, shed light on the precise measurement of the Hubble constant and its implications.

Resumen:

In the last decades, the $\Lambda$-CDM model have been supported by observations of the Cosmic Microwave Background (CMB), type Ia supernovae (SN Ia), the Hubble parameter and Baryonic Acoustic Oscillations (BAO), and have yielded cosmological parameters with precisions of the order of one percent (e.g. the CMB analysis). Nevertheless, there are still theoretical and observational claims that departs of the $\Lambda$-CDM paradigm. This opens the door to explore alternatives such as the $f(R)$-modified gravity theory, string-inspired models with a Gauss-Bonnet dilaton coupling, Horndeski gravity and massive gravity. In this context, we consider the mimetic gravity which is an interesting modification of the gravitational theory that provides a geometric description of dark matter and dark energy. This gravity theory is a Weyl-symmetric extension of General Relativity, related to the latter by a singular disformal transformation with extra degrees of freedom and these can mimic cosmological components. In this poster, we will present the dynamic description of the isotropic and homogeneous Friedmann-Lematre-Robertson-Walker cosmological models with spatial curvature coming from mimetic gravity theory. The phase space obtained allow us access to solutions that can represent different stages of the cosmic evolution. We therefore can obtain properties of the cosmological models that can be compared with the Observational Hubble database from the cosmic chronometers (OHD) and the Pantheon database from type Ia supernovae (PaSNe). In this poster, we will also present a brief discussion on the observational properties of the $\Lambda$-CDM model and models for mimetic fields with exponential potential (EP) and with quadratic rotational potential (QRP), with emphasis on the cosmological constraints provided by this study.

Resumen:

The chemistry of the early universe consisted mainly of simple atomic species and molecules composed of hydrogen and helium. Therefore, to understand the chemistry of the early universe it is necessary to know the chemical processes that these species underwent. Also, the interaction with the Cosmic Microwave Background (CMB) is the best test for determine the evolution and abundance of the primordial chemistry. To model the early chemistry, we will estimate the abundance of these species as a function of redshift using the chemistry package KROME. We focus in the $HeH^+$ molecule, because this molecule has a high dipole moment and is formed by quite abundant species. Also, its contribution to the optical opacity affecting the CMB. For this molecule we will explore new rates, such as dissociative recombination and photodissociation, and their impact on abundance. The importance of studying the formation and destruction processes of primordial molecules is that they allow us to estimate the abundance, which is important to understand the formation of the first stars in the universe.

Resumen:

The Next Generation Fornax Survey (NGFS) has been instrumental in advancing our understanding of various astrophysical phenomena. This survey features very deep stacks of images from visible (DECam u, g, i) to infrared (VIRCAM J, Ks) wavelengths with unprecedented care for photometric calibration standards. Building on this rich tradition, we present the first results of the ongoing effort to study the clusters in this survey, going beyond the local universe. So far, our methodology for studying cluster is comprised in a four-step pipeline: meticulous photometric analysis, photometric redshift calculation using Bayesian Photometric Z (BPZ; Benitez, N. et al 2004), cluster detection using PZWav (Gonzalez, A. 2014), and estimation of galaxy membership probabilities. We are also in the process of including a step to estimate the physical properties of these clusters. As to be expected, our preliminary results in the first of seven tiles (>~3 sq. deg. per tile) reveal an array of structures including voids and filaments, visualized using Voronoi Tessellations. Due to the gaps in the spectral coverage, between the challenges we face there are photometric redshift degeneracies, and thus, redshift deserts. Despite this, for the first tile we detect 37 clusters with 5-$\sigma$ confidence (20 being at 1.4>z>0.9). These early findings are validated by the detections at low redshift matching the DESI Legacy Survey clusters in this field in more than half of the cases. Although the coverage of NGFS is much smaller than other surveys, it reaches higher redshift, potentially opening for empirical conclusions to be drawn in this window to the universe in the galaxy evolution front.

Resumen:

Parameter bounds for the dark matter candidates can be obtained not only from astrophysical sources or large particle colliders but also from laser experiments. One of these experiments consists of shining a wall with a laser and trying to convert the photon into a dark matter candidate particle through an external magnetic field coupling, named light shining through the wall (LSW). On the other side of the wall, another magnetic field region would reconvert the weak interacting particle into a photon again before passing through a detector. We explore the possibility of implementing LSW to detect dark matter candidates, taking advantage of the power laser pulses achieved at the Extreme Light Infrastructure shortly.

Resumen:

In this contribution, we are interested in enforcing results reported in other works, where the main statement is that the general relativity formalism is not necessary to describe the physics of the halo around spiral galaxies. Then, an inter-median formalism between the classical Newtonian and the relativistic Tolman Oppenheimer Volkoff ones is used to model a halo filled with perfect fluid and equation of state obtained for the universal rotation curves of spiral galaxies. In order to keep the hydrostatic equilibrium the dark matter should have a nonzero pressure to compensate for the gravitational force of the mass contends in the halo. Then a state equation is demanded in order to accomplish this requirement and completes the set of space-time nonlinear gravitation field equations obtained from general relativity.

Resumen:

The work presented at this meeting is an extension of a work presented at a hole conference Black Holes held in Foz de Iguaz´u,(International Conference on Black Holes as Cosmic Batteries: UHECRs and Multimessenger Astronomy - BHCB2018 September 12-15, 2018 Foz do Igua¸cu, Brazil ) whose title was: “Type Ia Supernovae and fusion of black holes: Do they complement each other in measuring the expansion of the universe? Its objective is to answer, if it is possible to make measurements of cosmological distances, complementing type Ia supernovae with the merger of black holes, evaluating if it is possible to refine the measurement of the expansion acceleration of the Universe, through the detection of gravitational waves generated by the merging of holes black by comparing them with the intrinsic luminosity of type Ia supernovae. The methodology is shown used with the results obtained in the previous work, to contrast the simulation of results with the obtained result. In this work the methodology of the previous work is extended, contrasting the results virtual with those obtained in the publication of the work “A gravitational wave standard siren measurement of the Hubble constant”, applying a novel approach to measure the Hubble constant by means of waves gravitational forces, applying for the first time a revolutionary method proposed 30 years ago by Bernard Schutz using source GW170817, detected by Advanced LIGO and Advanced Virgo on August 17, 2017. The analysis of the gravitational waveform from the merger of black holes or neutron stars allows to estimate the distance, which allows us to compare, according to the environment of the host galaxy, in relation to to its environment, the comparison of light curves of supernovae, type Ia contrasting the results, in the distance and what is the result of H0.