A5002690859- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Dark Matter and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Black Holes and Theoretical Physics
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Stellar, planetary, and galactic studies
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Gaussian Processes and Bayesian Inference
- Relativity and Gravitational Theory
- Anomaly Detection Techniques and Applications
- Time Series Analysis and Forecasting
- Advanced Mathematical Theories and Applications
- CCD and CMOS Imaging Sensors
- Space Science and Extraterrestrial Life
- Earth Systems and Cosmic Evolution
- Calibration and Measurement Techniques
- Advanced Differential Geometry Research
- Scientific Research and Discoveries
- Data Visualization and Analytics
- Radio Astronomy Observations and Technology
- Remote Sensing in Agriculture
- Spectroscopy and Laser Applications
Universidade Federal da Bahia
2022-2025
Hospital Ana Nery
2024
Universidade Federal do Espírito Santo
2012-2024
National Observatory
2018-2023
Valongo Observatory
2020-2023
Laboratório Interinstitucional de e-Astronomia
2021
University of Geneva
2018-2020
The observational fact that the present values of densities dark energy and matter are same order magnitude, $$\rho _{\mathrm{de}0}/\rho _{\mathrm{dm}0} \sim \mathcal {O}(1)$$ , seems to indicate we currently living in a very special period cosmic history. Within standard model, density ratio one just at epoch can be seen as coincidental since it requires initial conditions early Universe. corresponding “why now” question constitutes cosmological “coincidence problem”. According model...
The results of joint analyses available cosmological data have motivated an important debate about a possible detection non-zero spatial curvature. If confirmed, such result would imply change in our present understanding cosmic evolution with theoretical and observational consequences. In this paper we discuss the legitimacy carrying out currently sets explore their implications for non-flat universe extensions standard model. We use robust tension estimator to perform quantitative analysis...
Since there is no known symmetry in Nature that prevents a non-minimal coupling between the dark energy (DE) and cold matter (CDM) components, such possibility constitutes an alternative to standard cosmology, with its theoretical observational consequences being of great interest. In this paper we propose new null test on evolution sector based time dependence ratio CDM DE densities which, $\Lambda$CDM scenario, scales necessarily as $a^{-3}$. We use latest measurements type Ia supernovae,...
Relaxing the conventional assumption of a minimal coupling between dark matter (DM) and energy (DE) fields introduces significant changes in predicted evolution Universe. Therefore, testing such possibility constitutes an essential task not only for cosmology but also fundamental physics. In previous communication [Phys. Rev. D99, 043521, 2019], we proposed new null test $\Lambda$CDM model based on time dependence ratio DM DE densities which is able to detect potential signatures interaction...
ABSTRACT Next-generation surveys will provide photometric and spectroscopic data of millions to billions galaxies with unprecedented precision. This offers a unique chance improve our understanding the galaxy evolution unresolved nature dark matter (DM). At scales, density distribution DM is strongly affected by feedback processes, which are difficult fully account for in classical techniques derive masses. We explore capability supervised machine learning (ML) algorithms predict content...
Early-type galaxies (ETGs) are reference systems to understand galaxy formation and evolution processes. The physics of their collapse internal dynamics codified in well-known scaling relations. Cosmological hydrodynamical simulations play an important role, providing insights into the 3D distribution matter mechanisms, as well validating methods infer properties real objects. In this work, we present closest-to-reality sample ETGs from IllustrisTNG100-1 simulation, dubbed "virtual-ETGs,"...
The discovery that we live in an accelerating universe changed drastically the paradigm of physics and introduced concept \textit{dark energy}. In this work, present a brief historical description main events related to cosmic acceleration basic elements theoretical observational aspects dark energy. Regarding perspective, outline some key milestones for tracing journey from Einstein's proposal cosmological constant type Ia supernovae results. Conversely, on theoretical/observational side,...
Abstract Early-type galaxies (ETGs) are reference systems to understand galaxy formation and evolution processes. The physics of their internal dynamics codified in well-known scaling relations. In this context, cosmological hydrodynamical simulations play an important role probing the physical origins relations by providing a controlled environment study galaxies, linking underlying processes, testing robustness observational inference methods. work, we present closest-to-reality sample...
Abstract We investigate the observational implications of a gravitational model wherein constant G and cosmological $$\Lambda $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>Λ</mml:mi> </mml:math> exhibit scale-dependent behavior at perturbative level, while preserving General Relativity (GR) field equations background. This is motivated by potential influence large-scale (infrared) Renormalization Group (RG) corrections to gravity constructed upon an effective action...
An interaction between dark matter and energy, proportional to the product of their energy densities, results in a scaling behavior ratio these densities with respect scale factor Robertson-Walker metric. This gives rise class cosmological models which deviate from standard model an analytically tractable way. In particular, it becomes possible quantify role potential dark-energy perturbations. We investigate impact this on structure formation process. Using (modified) CAMB code we obtain...
The next generation of galaxy surveys will allow us to test some fundamental aspects the standard cosmological model, including assumption a minimal coupling between components dark sector. In this paper, we present Javalambre Physics Accelerated Universe Astrophysical Survey (J-PAS) forecasts on class unified models where cold matter interacts with vacuum energy, considering future observations baryon acoustic oscillations, redshift-space distortions, and power spectrum. After providing...
The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will soon start to scan thousands square degrees northern extragalactic sky with a unique set $56$ optical filters from dedicated $2.55$m telescope, JST, at Javalambre Observatory. Before arrival final instrument (a 1.2 Gpixels, 4.2deg$^2$ field-of-view camera), JST was equipped an interim camera (JPAS-Pathfinder), composed one CCD 0.3deg$^2$ and resolution 0.23 arcsec pixel$^{-1}$. To demonstrate scientific...
The fact that Einstein's equations connect the space-time geometry to total matter content of cosmic substratum, but not individual contributions species, can be translated into a degeneracy in cosmological dark sector. Such makes it impossible distinguish cases where energy (DE) interacts with (DM) from dynamical non-interacting scenario using observational data based only on time or distance measurements. In this paper, non-adiabatic generalized Chaplygin gas (gCg) model, we derive and...
Models with non-gravitational interactions between the dark matter and energy components are an alternative to standard cosmological scenario. These models characterized by interaction term, a frequently used parameterization is $Q = 3ξH ρ_{x}$, where $H$ Hubble parameter $ρ_{x}$ density. Although current observations support such model for negative values of $ξ$, we show here that this interval $ξ$ leads predict violation Weak Energy Condition (WEC) density, regardless value...
Abstract We perform a general test of the ΛCDM and w CDM cosmological models by comparing constraints on geometry expansion history to those growth structure. Specifically, we split total matter energy density, Ω M , (for CDM) dark equation state, into two parameters each: one that captures geometry, another growth. constrain our using current data, including type Ia supernovae, baryon acoustic oscillations, redshift space distortions, gravitational lensing, cosmic microwave background (CMB)...
ABSTRACT The Javalambre Photometric Local Universe Survey (J-PLUS) is a 12-band photometric survey using the 83-cm JAST telescope. Data Release 3 includes 47.4 million sources. J-PLUS DR3 only provides star-galaxy classification so that quasars are not identified from other Given size of data set, machine learning methods could provide valid alternative and solution to quasars. Our objective classify sources into galaxies, stars, quasars, outperforming available classifiers in each class. We...
We propose a two parameters extension of the flat $\Lambda$CDM model to capture impact matter inhomogeneities on background evolution Universe. Non virialized but non-linearly evolving overdense and underdense regions, whose abundance is quantified using Press-Schechter formalism, are collectively described by effective perfect fluids $\rho_{\rm{c}},\rho_{\rm{v}}$ with non vanishing equation state $w_{\rm{c,v}}\neq 0$. These coupled pressureless dust, akin an interacting DM-DE scenario. The...
Reduced Relativistic Gas (RRG) is a useful approach to describe the warm dark matter (WDM) or warmness of baryonic in approximation when interaction between particles irrelevant. The use Maxwell distribution leads complicated equation state J\"{u}ttner model relativistic ideal gas. RRG enables one reproduce same physical situation but much simpler form. For this reason can be tool for theories with some sort "new Physics". On other hand, even without qualitatively new implementations,...
We consider the perturbation dynamics for cosmic baryon fluid and determine corresponding power spectrum a Λ(t)CDM model in which cosmological term decays into dark matter linearly with Hubble rate. The is tested by joint analysis of data from supernovae type Ia (SNIa) (Constitution Union 2.1), baryonic acoustic oscillations (BAO), position first peak anisotropy microwave background (CMB) large-scale-structure (LSS) (SDSS DR7). While homogeneous isotropic only marginally influenced baryons,...
Context. The galaxy total mass inside the effective radius is a proxy of dark matter content and star formation efficiency. As such, it encodes important information on baryonic physics. Aims. Total central masses can be inferred via dynamics or gravitational lensing, but these methods have limitations. We propose novel approach based machine learning to make predictions using simple observables from imaging spectroscopic surveys. Methods. used catalogs multiband photometry, sizes, stellar...