[Todos] Fwd: Reunion de Cosmologia en UNSAM, Buenos Aires - XV COSMO en AR

Sab Abr 12 11:01:22 -03 2025

********************************************
Secretaría Departamental de Física
secre2 en fisica.unlp.edu.ar
Cecilia Cafiero / Alejandro Chiquino
Facultad de Ciencias Exactas
Universidad Nacional de La Plata
******************************************** 

-------- Mensaje original -------- 

 		ASUNTO:
 		Reunion de Cosmologia en UNSAM, Buenos Aires - XV COSMO en AR

 		FECHA:
 		2025-04-11 16:16

 		REMITENTE:
 		Carlos Argüelles <carlosarguelles80 en hotmail.com>

 		DESTINATARIO:
 		Secretaría de Ciencia y Técnica <secyt en fcaglp.unlp.edu.ar>, Andrea
Corvalan <acorvalan en fcaglp.unlp.edu.ar>, Asistentes de Secretaria de
Fisica <secre2 en fisica.unlp.edu.ar>

Estimados 

Les agradezco si por favor podrian difundir esta reunion sobre
cosmologia, que tendra lugar en la Universidad de San Martin (UNSAM), en
capital federal el proximo miercoles. 

Saludos 

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
[1] 

Los esperamos el miércoles! 

Saludos cordiales, 

Carlos 
Diana 
Gabriel 
Martín 

Links:
------
[1] https://unsam.edu.ar/home/como_llegar.php
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