I will investigate the propagation of gravitational waves on curved spacetimes within the low energy effective field theory of gravity, where effects from heavy fields are captured by higher dimensional curvature operators. Depending on the spin of the particles integrated out, the speed of gravitational waves at low energy can be either superluminal or subluminal as compared to the causal...
As a modified gravity theory that introduces new gravitational degrees of freedom, the generalized SU(2) Proca theory (GSU2P for short) is the non-Abelian version of the well known generalized Proca theory where the action is invariant under global transformations of the SU(2) group. This theory was formulated for the first time in Phys. Rev. D 94 (2016) 084041, having implemented the required...
Horndeski gravity is the most general scalar tensor theory, with a single scalar field, leading to second-order field equations and after the GW170817 it has been severely constrained. In this talk, I will present an analog of Horndeski’s theory in the Teleparallel Gravity framework where gravity is mediated through torsion instead of curvature. It will be shown that, even though, many terms...
This work investigates a toy model for inflation in a class of modified theo-
ries of gravity in the metric formalism. Instead of the standard procedure —
assuming a non-linear Lagrangian f (R) in the Jordan frame — we start from
a simple φ 2 potential in the Einstein frame and investigate the correspond-
ing f (R) in the former picture. Such approach yields plenty of new pieces
of...
Modern cosmology is extensively studied by the scientific community in an attempt to answer many issues about the universe. The theoretical basis underlying all this theory is general relativity. However, there are other approaches such as modified theories of gravity that try to solve a series of problems in cosmology, particularly in the study of the early universe, a period known as cosmic...
Scalar-tensor theories represent extensions of Einstein's gravity through the inclusion of a scalar field with no-minimal coupling. An analysis of these theories has been carried out within the framework of non-degenerate theories (determinant of the Hessian matrix is zero). Therefore, it is feasible to increase the space of modified theories including the cases in which there is degeneracy,...
In this talk, I will discuss the dynamical properties of tracker quintessence models using a general parametrization of their corresponding potentials and show that there is a general condition for the appearance of a tracker behavior at early times. I will also discuss how to determine the conditions under which the quintessence tracker models can also provide an accelerating expansion of the...
In this talk we discuss the relation between topological mass generation of 2-forms and generalized Galileon theories for 2-forms involving the systematic construction of quartic Lagrangians in four dimensions. In terms of massless 1− and 2-forms $A$ and $B$ respectively, the mechanism of topological generation of mass arises as a consequence of the topological interaction term $B\wedge F$,...
In this work we study the possibility to obtain an accelerated expansion from arbitrary couplings between $p$-forms in a 4-dimensional space-time. The Lagrangian is built with couplings between 1- and 2-forms with kinetic functions of a scalar field $\phi$ (a quintessence field in this context). By using a dynamical system approach, we study the evolution of the fields in an anisotropic ...
We study some models where non-Abelian gauge vector fields endowed with a SU(2) group representation are the unique source of inflation and dark energy. These models were first introduced under the name of gaugeflation and gaugessence, respectively. Although several realizations of these models have been discussed, not all available parameters and initial conditions are known. In this work, we...
In the context of the dark energy scenario, the Einstein Yang-Mills Higgs model in the SO(3) representation was studied for the first time by M. Rinaldi (see JCAP 1510, 023 (2015)) in a homogeneous and isotropic spacetime. We revisit this model, finding in particular that the interaction between the Higgs field and the gauge fields generates contributions to the momentum density,...
The Generalized Chaplygin Gas (GCG) model is characterized by the equation of state $P = -A \rho^{-\alpha}$, where $A>0$ and $\alpha < 1$. The model has been extensively studied due to its interesting properties and applicability in several contexts, from late-time acceleration to primordial inflation. Nonetheless we show that the inflationary slow-roll regime cannot be satisfied by the GCG...
In this work, we explore upcoming cosmological proxies to constrain alternative cosmological models. We focus on a particular dark energy model with a non-negligible contribution during radiation domination epoch, and therefore, it could have introduced additional degrees of freedom on the Hubble parameter at that time. We consider probes that these candidates can be submitted in the future,...
The polarization pattern in the CMB fluctuations can leave an imprint of parity violation in the early universe through a positive measurement of cross-correlation functions that are not parity invariant. Does gravity violate parity? In this talk, I will show how the combination of the recent measurements from the Neutron Star Interior Composition Explorer (NICER) with the measurement of the...
The large scale structure bispectrum couples large scales (where general relativity is relevant) and short scales (where non-linearities are important) such that it contains information about the dynamics of the early universe in the squeezed limit. We start by performing a calculation which is non-linear and is based in General relativity under the weak field approximation with the purpose to...
We study a new class of vector dark energy models where multi-Proca fields $A_\mu^a$ are coupled to cold dark matter by a mass-type term. From here, we derive the general covariant form of the novel interaction term sourcing the field equations. This result is quite general in the sense that encompasses Abelian and non-Abelian vector fields. In particular, we investigate the effects of this...
In this paper, we study a triplet of inhomogeneous scalar fields, known as "solid", as a source of anisotropic dark energy. By using a dynamical system approach, we find that anisotropic accelerated solutions can be realized as attractor points for suitable parameters of the model. We compliment the dynamical analysis with a numerical solution whose initial conditions are set in the deep...
An early period of inflation driven by a rolling scalar field must end by successfully reheating the Universe into the radiation-dominated era before the time of Big Bang Nucleosynthesis. In my talk I consider inflaton decays (both perturbative and resonant) into SM particles, which acquire their mass via couplings to the SM Higgs boson. The particular decays may temporarily be blocked due to...
In the presence of magnetic fields, gravitational waves are converted into photons and vice versa. We demonstrate that this conversion leads to a distortion of the cosmic microwave background (CMB), which can serve as a detector for MHz to GHz gravitational wave sources active before reionization. The non-observation of such distortions gives rise to bounds exceeding laboratory constraints....
In the Starobinsky model of inflation, the observed dark matter abundance can be produced from the direct decay of the inflaton field only in a very narrow spectrum of close-to-conformal scalar fields and spinors of mass $\sim 10^7$ GeV. This spectrum can be, however, significantly broadened in the presence of effective non-renormalizable interactions between the dark and the visible sectors....
I will discuss the fate of the U(1) gauge coupling under the inclusion of vector-like fermions in the Standard Model. Then, motivated by results on quantum gravity contributions to the running of gauge and Yukawa couplings, I will talk about the effect of simple but general corrections to the running of those couplings from the EW to large enough energy scales. One of our goals is to have an...
We scrutinise the widely studied minimal scotogenic model of dark matter (DM)
and radiative neutrino mass from the requirement of a strong First order electroweak phase
transition (EWPT) and observable gravitational waves at future planned space-based experiments.
The scalar DM scenario is similar to inert scalar doublet extension of the standard model
where a strong ?first-order EWPT...
We study the consequence of a non-standard cosmological epoch in the early
universe on the generation of baryon asymmetry through leptogenesis as well as dark matter abundance. We consider two different non-standard epochs: one where a scalar field behaving like pressure-less matter dominates the early universe, known as early matter domination (EMD) scenario while in the second scenario, the...
We propose a baryogenesis mechanism where axion’s rotation in the potential is initiated by explicit Peccei-Quinn symmetry breaking in the early Universe and gives rise to the observed baryon asymmetry. With the aid of the neutrino Majorana mass term, the Peccei-Quinn charge associated with the rotation is sequentially transferred to the baryon asymmetry. QCD axion dark matter can be...
We have considered the possibility of probing the left-right symmetric model (LRSM) via cosmic microwave background (CMB) by adopting the minimal LRSM with Higgs doublets, also known as the doublet left-right model (DLRM), where all fermions, including the neutrinos, acquire masses only via their couplings to the Higgs bidoublet. There exist additional relativistic degrees of freedom, because...
In this talk we will review the cosmological implications of a scalar field dark matter model when considering an Axion-like potential. We will analyze some cosmological observables such as the 3D and 1D matter power spectrum, as well as how some physical quantities such as the growth factor of the perturbations and its velocity depend explicitly on the wavenumber in this type of models. We...
Topological defects–such as domain walls, cosmic strings, and magnetic monopoles–are expected to appear during a phase transition in Grand Unified Theories of particle physics. Such monopoles were estimated to be the dominant matter during the early universe. However, this prediction is in tension with the fact that monopoles have not been observed. The former is known as the cosmological...
Within the limits of the present cosmological observations, an interacting model of holographic dark energy and matter in a five-dimensional spherically symmetric space-time setting has been analyzed within the framework of Brans-Dicke Theory. We obtain a model universe that undergoes super-exponential expansion. It is predicted that the universe is isotropic and will be continuously dark...
The Cosmic Microwave Background (CMB) is an open window to the early Uni-
verse. To compute the CMB Spectrum we need to perturb the FLRW universe since
our universe is no longer homogeneous and isotropic at small scales. Furthermore,
the interaction between photons and electrons induces a perturbation in the photons
temperature. This interaction can be described by the Boltzmann equations....
Uno de los grandes retos de la cosmología es la descripción de la distribución de la materia a gran escala. Para esto, presentamos los resultados de nuestra investigación,la cual fue recientemente aceptada para publicación en el MNRAS Letters (2008.08164). En el artículo proponemos estudiar la red cósmica como un grafo ($\beta$-Skeleton), dada su estructura filamentar. Esto nos permite...
Galaxy superclusters are starting to be routinely detected in observational data of the large scale structure of the Universe.
Diverse definitions and algorithms have been presented in the literature with the expectation to build a compelling framework to study superclusters.
In this work we present the strengths of defining superclusters as watershed basins in the divergence velocity...
The introduction of right-handed chirality partners for neutrinos allows the calculation of deviations in the effective number of degrees of freedom in the early universe, which could be probed by new observations like CMB-SO4 or Planck+BAO. The presence of these sterile neutrinos can be useful when proposing dark matter candidates and when different physical phenomena such as the...
Los cosmólogos han propuesto que una sustancia misteriosa llamada quintaesencia, o energía oscura, puede explicar por qué nuestro universo se está acelerando. ¿Pero de qué está hecha?, ¿Qué produce la expansión acelerada del universo?,¿Cuál fue la causa de la hipotética era inflacionaría?, en fin son muchas las preguntas acerca de la evolución y desarrollo del universo.Hoy día, se está...
Los vacíos cósmicos, regiones de decenas de Megaparsec con una densidad de materia menor a la media cosmológica, son un laboratorio de estudio para la cosmología. La morfología y evolución de estos vacíos se ve influenciada por el contenido de materia-energía del Universo.
En la última década, estudios analíticos mostraron que sería posible utilizar la caracterización geométrica de los vacíos...
La red cósmica es el patrón que surge al observar la distribución de materia en escalas de decenas de Megaparsec.
Esta estructura se revela a través de observaciones de la distribución de galaxias.
El estudio estadístico de estas distribuciones se hace en su mayoría a través de la función de correlación de dos puntos.
Otra opción es el estudio a través de las propiedades de conectividad de...
In this talk I present the study of Higgs boson observables at the LHC and their impact on electroweak baryogenesis in the context of Standard Model effective field theory with the inclusion of dimension 6 operators of Higgs and fermion fields. I will also discuss how these new terms can generate an electric dipole moment of leptons and thus add further constraints to produce the baryon...
In recent work (Yang et al., 2007.03150) we showed some examples on how to use the mark weigh-
ted correlation functions (MCFs), to study the large scale structure of the Universe. In this talk I will
summarize that work and show how MCFs exhibit distinctive peaks and valleys that do not exist in the standard correlation functions. Although, MCFs are not suited to be used as “standard...
The spatial distribution of galaxies on large scales forms a striking filamentary pattern known as the cosmic web. Measuring and characterizing this pattern is one of the main goals in cosmology. There are algorithms that can perform this task using the full dark matter distribution as an input. However, in observations, the dark matter distribution is not observable. To bypass this limitation...
Baryon Acoustic Oscillations provide a standard ruler for measuring distances far back into the history of the Universe. The Galaxy-Galaxy two-point correlation function (2PCF) is the standard proxy for the measurement of the BAO scale using large-scale spectroscopic surveys. There is, however, information beyond the two-point statistics encoded in the galaxy distribution that can be extracted...
The bias ($b$) is a parameter that relates the clustering of a set of objects with the clustering of underlying dark Matter. It has been found that b depends on various galaxy properties, this phenomenon is usually known as Galaxy Assembly Bias. In general, b depends on how the galaxies have formed. We quantify the galaxy assembly bias of simulated galaxies at $z = 0$ with stellar masses $...
In this talk we introduce a pseudo-spectral approach based on the spin-weighted spherical harmonics for numerically treating the evolution of inhomogeneous and anisotropic cosmological models with spatial topology S1XS2.
This research analyzes and describes the movement of extended N-bodies endowed with an internal structure which interact gravitationally in an isolated and self-gravitating system. For it is made use of the Newtonian and Einsteinian theories, understanding Newton’s theory as a limit of the general relativity theory.
For this we make a mathematical approach to the equations that describe the...
In recent years tests on General Relativity have been made and numerical simulations played an important role, in particular Numerical Relativity (NR) simulations have been used in the understanding of astrophysics phenomena. Recent works have shown the importance of NR in the case of cosmology using cosmological perturbations for a flat expanding universe with a perfect fluid background...
Two methods for mass profiles reconstruction in disc-like galaxies are presented in this work, the first is done with the fit of the rotation curve based on the data of circular velocity which are obtained observationally in a stars system, while the other method is focused in the Gravitational Lensed Effect (GLE). For these mass reconstructions, two routines developed in the language of...
Provide techniques and models that lead describe large structure`s formation in the universe, is a great challenge in cosmology. In this work, matter spectrum potential at second order was reconstructed using semi-analytical methods, in this context general equations of movement for dark matter fluid are constructed. Due to the complexity in the solution of this kind of equations, a solution...
The observation of GW170817 binary neutron star (BNS) merger event has imposed strong bounds on the speed of gravitational waves (GWs) locally, inferring that the speed of GWs propagation is equal to the speed of light. Current GW detectors in operation will not be able to observe BNS merger to long cosmological distance, where possible cosmological corrections on the cosmic expansion history...
