In this talk we consider an effective parametrization for a scalar field that evolves in time, known as K-essence, to describe Dark Energy in the framework of FLRW metric. In the past, we constrained the free parameters of this model with luminosity distances of supernova Ia up to redshift 1.4. Now, we introduce different cosmological proxies, as BAO and CMB data from Planck, to complete the...
We study the dynamics of dark energy in the presence of a 2-form field coupled to a canonical scalar field $\phi$. We consider the coupling proportional to $e^{-\mu \phi/M_{\rm pl}} H_{\alpha \beta \gamma}H^{\alpha \beta \gamma}$ and the scalar potential $V(\phi) \propto e^{-\lambda \phi/M_{\rm pl}}$, where $H_{\alpha \beta \gamma}$ is the 2-form field strength, $\mu, \lambda$ are constants,...
In this talk we will show that one can construct regular black holes solutions by reversing the Penrose singularity theorem and by tuning the null energy condition appropriately. In particular, we will show the existence of spherically symmetric regular black hole solutions with exotic topologies and we will classify them by using some kind of charge related to the trace of the energy momentum...
Large galaxy redshift surveys have become a standard tool in observational cosmology in the last three decades. The correlation function of the galaxy distribution inferred from those surveys is widely recognized as a strong cosmological probe. This has motivated new surveys such as the Dark Energy Spectroscopic Instrument (DESI) to increase by an order of magnitude the number of mapped...
We propose two methods for robustly estimating extragalactic distance errors thopughout the cosmic distance ladder. Frequentist methods they fail to explain both the scatter between different measurements and the effects of skewness in the metric distance probability distribution. We compare the performance of frequentist methods versus our proposed measures for estimating the true variance of...
Constraining cosmological parameters from observational data is one of the main challenges in observational cosmology. To address it, we present results based on the $\beta$-skeleton, a new technique designed to find a graph describing the underlying web structure in spatial point distributions. From the $\beta$-skeleton we define an entropy scalar and show how it can be used a cosmological...
Large underdense regions in the Large Scale Structure (LSS) of the Universe, also known as voids, are a prominent features of the cosmic web that can also be used as a cosmological probe. In this talk, I will present a new void-finding algorithm that can be applied to both observational and simulated data. The algorithm is based on the $\beta$-Skeleton, an algorithm widely used on machine...
The galaxy distribution on large scales is not uniform, it follows a web-like pattern known as the cosmic-web. This pattern can be completely explained by the galaxies forming inside of dark matter halos. Therefore, the galaxy distribution can be related to the underlying dark matter distribution. This relationship, known as galaxy bias, can be used to understand the varied physics process of...
Los avances en cosmología observacional dependen en gran medida de la interpretación de grandes levantamientos (surveys) espectrométricos. Los continuos avances tecnológicos ahora permiten que decenas de miles de espectros sean registrados en una noche de observación. Gracias a esta situación, es necesario abordar el problema de clasificación espectral de una manera mas eficiente que la...
Understanding the large scale dark matter distributions in the local Universe is one of the main goals in physical cosmology. However, this distribution is not directly observable and must be inferred from the observed galaxy distribution from large redshift surveys such as the Sloan Digital Sky Survey (SDSS) data or the upcoming of the Dark Energy Spectroscopic Instrument (DESI). In this talk...
when the velocities of a group of galaxies converge to a single structure, they are
said to be part of the same supercluster. This structure has quantifiable properties
such as mass, volume, density and inertia, among others. Here we compare cosmolo-
gical simulations of N-bodies with the results obtained by Tully et al. (2014) when
determining these characteristics in Laniakea, our local...
The cosmological observations are consistent with a homogeneous and isotropic universe at large
scales which favours the use of scalar fields as generators of the primordial and late inflationary
periods. However, in the Standard Model of Particle Physics, whose action is invariant under
SU(3)C × SU(2)L × U(1)Y local transformations, there exist vector fields which are the messengers
of the...
Inspired in the Standard Model of Elementary Particles, the Einstein Yang-Mills Higgs action with the Higgs field in the SU(2) representation was proposed in Class. Quantum Grav. 32 (2015) 045002 as the element responsible for the dark energy phenomenon. We revisit this action emphasizing in a very important aspect not sufficiently explored in the original work and that substantially changes...
Large scale galaxy surveys have shown its ability to constraint cosmological parameters mostly through the analysis of the correlation function and the power spectrum.
The Nyquist criterion underlies the design of these large surveys by imposing a condition on the minimal number density of tracers required to recover the matter density signal corresponding to a given wave-number.
Here, we...
I will briefly discuss the simplest scenarios for primordial black hole formation, and the reason behind the recent interest in these objects. I will then show that one of the predictions in these scenarios is that primordial black hole spin is small, in the sense that the spin parameter is of the order of a percent.
The generalized SU(2) Proca theory is the only modified gravity theory, nowadays, able to accommodate in a natural way a configuration of vector fields which is compatible with the homogeneous and isotropic nature of our Universe. In a previous work, and employing just one of the three pieces that conform the L_4 Lagrangian, we were able to uncover a self-tuning mechanism that drives an...
A rather minimal possibility is that dark matter consists of the gauge bosons of a spontaneously broken symmetry. I will discuss the possibility of detecting the gravitational waves produced by the phase transition associated with such breaking. Concretely, I will focus on the scenario based on an 𝑆𝑈(2)_D group and argue that it is a case study for the sensitivity of future gravitational wave...
Inflation driven by a scalar tensor model with non-minimal derivative coupling to the Einstein tensor is considered. The power spectra for primordial scalar and tensor fluctuations is analyzed. For the analyzed potentials it is shown that the models can be made compatible with the current observational data.
Assuming the detection of a weakly interacting massive particle (WIMP) of dark matter (DM) occurs, its particle physics properties (mass $m_{\chi}$, and thermally averaged DM annihilation cross section $\langle\sigma v\rangle$) are known and these disagree with the usual freeze-out mechanism, one can either look for different DM production mechanisms or for alternative cosmological scenarios....
In this talk we use the eikonal approximation to impose constraints on the Horndeski’s vector-tensor theory. We explore the modifications imposed by Horndeski's theory on some very basic aspects of geometric optics such as light propagation on null geodesics, the geodesic deviation equation, photon creation, among others. We illustrate our results in Friedmann-Lemaître and Schwarzschild...
The advanced Laser Interferometer Gravitational Observatory (LIGO) and the VIRGO interferometer announced the detection of gravitational waves (GW170817) from the merger of a binary neutron star, as well as the associated gamma ray burst (GRB170817A), $1.7$ s after the gravity wave detection. An immediate consequence of these detections is that gravity waves propagate at light speed in one...
We use conformal symmetry to constrain the shape of inflationary correlators in the presence
of long-lived vector field perturbations. Applying conformal Ward identities, we derive general
expressions, up to amplitudes and normalization factors, for the two and three point correlators
in the presence of vector fields mediated by the interaction f(?)
Fμ?Fμ? + ? ˜ Fμ?Fμ?
?
, where f(?)
is a...
Assuming that inflation is followed by a phase where the energy density of the Universe is dominated by a component with a general equation of state, we evaluate the spectrum of primordial gravitational waves induced in the post-inflationary Universe. We show that if the energy density of the Universe is dominated by a component ϕ before Big Bang nucleosynthesis, its equation of state could be...
Smarr relations in terms of thermodynamical quasilocal variables are obtained for Schwarzschild and Reissner-Nordström black holes. Our treatment is based on Brown and York's Euclidean path integral approach for gravitational thermodynamics. The resulting expressions allow us to construct the relation between the quasilocal energy obtained in this setting and the Komar and Misner-Sharp...
