Colloquium Archives

Robert Bluhm, Colby College

Topic: "Testing Lorentz Symmetry"  (Video)

ABSTRACT: Lorentz symmetry is a fundamental component of the standard model in particle physics and of general relativity.  However, in recent years, the idea that Lorentz symmetry might not hold exactly due to effects arising at the Planck scale in a quantum theory of gravity (such as string theory) has received much attention.  This talk will look at theoretical investigations of Lorentz tests, which use a framework known at the Standard-Model Extension. A variety of recent phenomenological tests of Lorentz symmetry will be examined.

Bob Rutledge, McGill University

Topic: "Measuring the Dense Matter Equation of State with International X-Ray Observatory"  (Video)

Abstract: Observations of the thermal emission from hydrogen atmosphere neutron stars can provide simultaneous measurements of neutron star masses and radii, made possible with future large-collecting area, high spectral resolution X-ray observatories.   In this talk, I will briefly review the observational situation of neutron star radii measurements using this technique, where future observations are headed, and how observations with the proposed International X-ray Observatory, can provide tight, simultaneous measurements of both neutron star masses and radii. These methods will be sufficient for determining the dense matter equation of state.

Lisa Kaltenegger, Harvard-Smithsonian Center for Astrophysics

Topic: "Characterizing 'Pale Blue Dots' in the Sky - Spectral Fingerprint of Habitability"  (Video)

ABSTRACT: After a decade rich in giant exoplanet detections, the detection and characterization of Earth-like planet is approaching rapidly with dedicated space observatories already in operation (Corot) or in development phase. How can we detect and characterize them? Can they be habitable? In my talk I will focus on the fascinating new results and models for Earth to super Earths as well as how we can read a planet's spectral fingerprint and characterize if it is potentially habitable.