School of Natural Sciences

The Continuing Search for Planet Nine

Matthew Holman
Harvard-Smithsonian Center for Astrophysics
October 15, 2019

Several lines of evidence, both theoretical and observational, indicate that additional planets in the outer solar system remain to be discovered.  Most recently, attention has been focused on 'Planet Nine',a few Earth mass planet with a moderate inclination at a distance of a few hundred AU (Trujillo & Sheppard 2014, Batygin & Brown 2016, Brown & Batygin 2016).  I will review this evidence for the existence of this body and will present a variety of approaches that are being used to find it.

A brief review of some work on BPS states, wall-crossing, hyperkahler geometry, Hitchin systems, etc.

Greg Moore
Rutgers University
September 18, 2019

This talk will give a brief overview focused on six papers written by D. Gaiotto, G. Moore, and A. Neitzke
loosely centered around the topics mentioned in the title. The papers are on the arXiv. 
Background reading:  Some short reviews are: 
https://arxiv.org/pdf/1211.2331.pdf
https://arxiv.org/pdf/1308.2198.pdf
https://arxiv.org/pdf/1412.7120.pdf