Friday, 8 January 2016

Implications in Astrophysics

I'm at a conference called "Recent Trends in Nuclear Structure and its Implications in Astrophysics".  They invited me here to come and talk, and I have indeed come and talked.  I don't consider myself to be a nuclear astrophysicist, though my two most cited papers are on neutron stars and the constraints put on their properties but the nuclear interactions that determine their structure. 

I wanted to make sure my talk was on-topic, though, so I had a think about what the implications of my work for astrophysics were, as per the title of the conference.  Fortunately for me, some of the speakers (like Umesh Garg from Notre Dame) spoke before me and essentially covered why the measurement and theoretical calculation of giant resonances, for example, are important astrophysical input.

The Giant Monopole Resonance (GMR) is an excitation mode of the nucleus which is sometimes called the breathing mode as it can be likened to an oscillatory expansion and contraction of a nucleus, like the expansion and contractions of lungs as one breathes.  It's an excitation mode found in all nuclei and it tells us something about how the nuclear interaction provides a restoring force when the nucleus is squashed into higher density, or rarefied into lower density.  This understanding of the density-dependence of the nuclear interaction is vital for understanding how neutron stars form.  Neutron stars are large nuclei in which the core density is higher than in normal nuclei -- not by factors of 100s, but enough that we need to do something more than look at nuclear ground states to learn about it.  The GMR gives such a way.  To link the properties of the GMR to the neutron star, though, the best one can do is to develop a theory which consistently gives correct reproduction of GMR properties, and to then use to for neutron star calculations (which are then compared to observational data).  This is where my calculations come in.  Hopefully I managed to convey a bit of that in my talk.  I've had a few people come up to me after and say that they enjoyed my talk and thought it was very clear and understandable, which is nice.  This is sometimes accompanied by questions which appear to suggest my talk was not as understandable as it could have been.

The image attached is the from a dance show put on for the conference attendees before the dinner on Wednesday.  It is a traditional dance local to the state of Odisha, where the conference is taking place.  It was a pretty cool dance.  The colour of the picture has not been changed;  there was a pretty trippy psychedelic light show to accompany the dancing and the music.