Mini-Symposium on Gravitational Waves with 2017 Nobel Laureate Prof. Rainer Weiss

On Thursday 31st of May the Finnish Physical Society and Department of Physics, University of Helsinki organized a Mini Symposium on Gravitational Waves: Prof. Rainer Weiss, the Nobel Laureate in Physics 2017for decisive contributions to the LIGO detector and the observation of gravitational waves". The other speakers of the symposium will be Prof. Mark Hindmarsh University of Sussex/University of Helsinki, Prof. Norbert Langer, University of Bonn, and Prof. Stephen Smartt, Queen’s University of Belfast.

Location: Exactum A111, University of Helsinki
(street address: Gustaf Hällströmin katu 2, 00560 Helsinki )

Schedule on Thursday, May 31st
10:00–10:10 Welcome (Kaarle Hämeri)
10:10–11:00 Rainer Weiss: The beginnings of gravitational wave astronomy
11:00–11:30 Norbert Langer: The astounding evolution of massive binary stars towards merging black holes
11:30–12:00 Coffee
12:00–12:30 Stephen Smartt: Kilonovae and the birth of multi-messenger astronomy 
12:30–13:00 Mark Hindmarsh: Observing the early Universe with gravitational waves  

The workshop was also open to a general audience.

The abstracts are below.

Rainer Weiss
Massachusetts Institute of Technology
on behalf of the LIGO Scientific Collaboration

The beginnings of gravitational wave astronomy

The first detection of gravitational waves was made in September 2015 with the measurement of the coalescence of two ~30 solar mass black holes at a distance of about 1 billion light years from Earth. The talk will provide a review of more recent measurements of black hole events as well as the first detection of the coalescence of two neutron stars and the beginning of multi-messenger astrophysics. The talk will end with a discussion of some prospects for the field.

Short bio: Rainer Weiss, born Sept 29, 1932 Berlin, Germany, MIT BS 1955, PhD 1962, Tufts University Physics faculty 1960-1962, Post doc Princeton 1962-1964, MIT Physics faculty 1964-2001, emeritus 2001---, Adjunct Professor of Physics LSU 2001--- . Primary areas of research: Atomic clocks, Cosmic background radiation measurements, Gravitational wave detection.

Mark Hindmarsh, University of Sussex/University of Helsinki

Observing the early Universe with gravitational waves

Our new ability to observe gravitational waves gives a powerful way to search for new physics in the very early Universe.  I will survey possible signals, and their prospects for discovery, particularly at the future space-based gravitational wave detector LISA.

Norbert Langer, University of Bonn

The astounding evolution of massive binary stars towards merging black holes

Most massive stars are born in binary or multiple systems. However, for massive binaries to produce merging black holes is all but natural. Major obstacles are the tendency of stars to expand to giant dimension when they age, and the power of supernova explosions to disrupt even close binary systems. I review which binaries can overcome these problems, how their number depends on their cosmological distance, and how the gravitational wave measurements revolutionize our understanding of massive binary evolution and nucleosynthesis.

Stephen Smartt, Queen's University Belfast

Kilonovae and the birth of multi-messenger astronomy 

I will describe the remarkable discovery of the first electromagnetic counterpart to a gravitational wave source. The merging neutron star source  GW170817 was temporally and spatially coincident with a short gamma ray burst and several teams located a transient optical source within the  LIGO-Virgo skymap within 12 hours. A worldwide observational campaign on telescopes from x-ray to radio immediately started showing that this electromagnetic transient was unlike any other observed to date. The UV to near-infrared emission showed that high velocity, low mass material  was ejected and powered by the radioactive decay of heavy r-process elements. I will review this discovery and show how the electromagnetic radiation is consistent with models describing what we expect to see when two neutron stars merge.