APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Peter Nugent (Department Head for Computational Science Computational Research Division Lawrence Berkeley National Laboratory (LBNL))
Title: Precision Cosmology from Gravitationally Lensed Supernovae
Date (JST): Thu, Feb 07, 2019, 14:00 - 15:00
Place: Seminar Room A
Related File: 2253.pdf
Abstract: In 1929 Edwin Hubble rocked the physics community with his
announcement that the universe was expanding - characterized shortly
thereafter by his eponymous constant. Nearly 80 years later the field
of cosmology has advanced tremendously with the discoveries of the
accelerated expansion of the universe and precision measurements of
both the universe's mass and energy densities. Amazingly, the most
contested value in cosmology today is the first one that was measured,
Hubble's Constant. There is currently a 3+ sigma disagreement between
local values, determined by supernovae and a maser, and distant ones
from Baryon Acoustic Oscillations and the Cosmic Microwave
Background. This implies that there are unknown systematics in either
(or both) measurements or new physics. The key to unraveling this
mystery lies in a method first proposed in 1964 by Sjur Refsdal - the
measurement of time delays from gravitationally lensed supernovae. In
the past year we have made great strides towards this goal with the
discovery of the first multiply lensed Type Ia supernova and a new
method which will increase the discovery rate of these objects by over
an order of magnitude in the next decade. Here I will discuss this new
tool for precision cosmology.