[Todos] Reunión de Cosmologia en UNSAM - Buenos Aires - XV Cosmo en ar

[Carlos Argüelles]

Estimado/as.

Este miércoles, 16/04, a partir de 10h, se llevará a cabo en el campus de la UNSAM la XV jornada Cosmo en ar.
El evento tendrá lugar en el aula 14 del edifício Tornavías, facilmente accesible por vários medios de transporte.
A continuación, enviamos la programación completa del evento y, al final, información sobre cómo acceder al lugar de las charlas.

10:00-11:00hs: Nahuel Miron Granese (DF/UBA)

Título: Early universe, non-ideal phenomena and their large-scale cosmological signatures

Resumen:

The early universe provides a unique setting to probe non-ideal and non-equilibrium physics through the imprints left on large-scale cosmological observables. In this talk, we will explore a range of such non-ideal phenomena that can affect the evolution of perturbations in fields like the cosmic microwave background (CMB), primordial gravitational waves (GW), and primordial magnetic fields. We will particularly focus on two specific scenarios: 1) The influence of self-interacting species within the dark sector on primordial GW and CMB B-mode polarization, and their implications for estimating the observable tensor-to-scalar ratio, 2) The development of a simplified effective framework based on kinetic theory for modeling matter during reheating, incorporating interactions, fluctuations and dissipative processes. This could complement the standard Lagrangian field-theoretic approach, aiming to capture a more realistic evolution.

11:00-11:30hs: Intervalo de café

11:30-12:30hs: Dr. Félix Mirabel (IAFE-UBA)

Título: Unusual Change in the Relativistic Jets of the Black Hole Transient GRS 1915+105

Resumen:

We compare observations at radio wavelengths made along three decades toward the prototypical Galactic microquasar source of apparent superluminal jets. In the year 2023 the source presented major changes with respect to the historical values since 1994. The position angle of the bipolar ejecta in the plane of the sky and the inclination angle of the flow with respect to the line of sight, each changed by about 20◦. These unusual changes took place within a year or less. Our analysis indicates that during 2023 the plane of the accretion flow to the black hole was aligned with the line of sight, which explains the almost complete X-ray obscuration, and high mid-infrared luminosity observed with the James Webb Space Telescope (JWST) in that epoch. These unusual changes are in agreement with the Lense-Thirring effect, where the axis of the tilted accretion flow around theKerr black hole will transition to align with the spin of the black hole. We will discuss the possible cause of these unusual changes in the relativistic jets from this black hole.

12:30-14:00hs: Almuerzo

14:00-15:00hs: Santiago Collazo (IALP)

Título: Direct detection of fermionic sub-MeV dark matter using Xenon based detectors

Resumen:

Recent astrophysical analysis on Galactic scales about the distribution of dark matter provide strong hints on its nature. The evidence span from relativistic image in SgrA*, to stelar orbits at mili parsec scales, all the way to the Milky Way rotation curve and stellar streams up to ~ 100 kpc. This predictions suggest that fermionic dark matter of sub-MeV mass can act as a proper candidate. Supposing that the dark matter candidate is a right-handed neutrino with a mass between 100 keV and 200 keV, and considering an effective electromagnetic channel of a more general four-fermion interaction, we study the ionization events rate induced by this candidate on electrons bounded to Xenon atoms. We also include the ionization form factor which characterizes the quantum mechanic physics of the atom, improving a previous model applied to the same scenario. In addition, we have computed exclusion regions ruling out different right-handed neutrino candidates and the coupling constant involved in the interaction with the bounded electron.

15:00-15:30hs: Intervalo de café

15:30-16:30hs: Karen Nowogrodzki (IS-ICAS/ICIFI/UNSAM)

Título: Microlensing with LSST: simulation, classification, and follow-up observations from CASLEO

Resumen:

Among the transient events that LSST will observe is microlensing, a phenomenon where a massive object passes along the line of sight between an observer and a light source, bending the light and causing the image to brighten. The main objective of this work is to assess the detection and characterization of microlensing events and constrain the properties of the lensing objects, using data from the LSST at the Vera C. Rubin Observatory. The ongoing research encompasses three interconnected projects that will help us prepare for LSST data: 1) a microlensing event classifier using MicroLIA to assess the detection of such events with the ELAsTiCC dataset (simulated LSST-like light curves), 2) a pipeline for inserting and extracting light curves in LSST simulations (DP0), enabling the evaluation of light curve reconstruction and the constraint of parameters, and 3) follow-up observations with the HSH telescope at CASLEO to contribute to the global characterization of microlensing events, in collaboration with the OMEGA international network. This project aims to both develop the end-to-end microlensing process, from target selection to light curve assembly and fitting, and to prepare for real-time follow-up of microlensing events detected by the LSST. The extracted light curves from DP0 will be used to train and refine MicroLIA’s classifier while also providing hands-on experience with the Rubin pipeline. Meanwhile, ongoing HSH observations of microlensing events will help optimize the workflow for following up on LSST-detected events.

Cómo llegar al campus de la UNSAM y al edifício Tornavías
(ver las anotaciones en el mapa en attach)

* Viniendo en tren o en auto

La estación Miguelete de la línea Mitre (Ramal José León Suarez) los deja prácticamente al lado del campus.
Salir de la estación hacia la derecha y caminar hasta Rodriguez Peña 2860.

En auto, entrar por Rodriguez Peña 2860. Ustedes serán direccionados al estacionamiento de visitantes.

El campus posee un servicio de micro-omnibus eléctrico que sale próximo de la entrada por Rodriguez Peña (ver mapa) y los lleva hasta el Tornavías.
Otra opción es hacer el mismo trayecto caminando por el campus (son aproximadamente 6 cuadra).

* Viniendo en taxi o transporte por aplicación: bajar directamente en la entrada de 25 de Mayo y Francia, cercana al Tornavias

Los colectivos : 21, 28, 57, 78, 87, 106, 117, 123, 161, 169, 176, también llevan al campus de la UNSAM

Para mas informaciones, ver: https://unsam.edu.ar/home/como_llegar.php

Los esperamos el miércoles!

Saludos cordiales,

Carlos
Diana
Gabriel
Martín

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