BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:5
UID:UW-Physics-Event-8409
DTSTART:20231109T203000Z
DTEND:20231109T213000Z
DTSTAMP:20260414T005752Z
LAST-MODIFIED:20231106T174051Z
LOCATION:5310 Chamberlin or https://wipac-science.zoom.us/j/9425427722
 2?pwd=QVJ1dHNCaFdmYnk1Vzk2TWJuQ3RwUT09
SUMMARY:Exploring New Physics with Background Radiation Fields\, NPAC 
 (Nuclear/Particle/Astro/Cosmo) Forum\, Justin Finke\, Naval Research L
 abs
DESCRIPTION:I will explore the following topics:  (1) I will discuss m
 odeling the ultraviolet through infrared Extragalactic Background Ligh
 t (EBL)\, which is the background light from all of the stars and dust
  that have existed in the observable universe.  This radiation field c
 an absorb gamma-rays to produce electron-positron pairs\, and can thus
  be probed with gamma-ray observations\, as well as optical and infrar
 ed surveys.  I will discuss what we can learn about star formation and
  other physics from it.  (2) I will discuss the brightest gamma-ray bu
 rst (GRB) ever observed\, GRB 221009A.  Fewer very-high energy (VHE) g
 amma-rays from this GRB are absorbed by the EBL than models predict\, 
 which may be an indication of new physics.  I will discuss how VHE obs
 ervations of this GRB can be explained by Lorentz invariance violation
  (LIV).  Lorentz invariance is one of the fundamental symmetries of re
 lativity\, and its violation is consistent with some beyond Standard M
 odel theories.  (3) Astrophysical gamma-rays can also be absorbed by a
  much closer source of optical photons than the EBL\, namely\, by phot
 ons from the Sun.  I will discuss how observations of absorption of as
 trophysical gamma-rays by solar photons could be used to probe LIV.
URL:https://www.physics.wisc.edu/events/?id=8409
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