Vanderbilt initiative for gravity, waves, and fluids

VandyGRAF Initiative

VandyGRAF Initiative

The Vanderbilt Initiative for Gravity, Waves, and Fluids is an interdisciplinary research venture providing mathematicians, physicists, and astrophysicists with the resources and space to connect and collaboratively work on problems of outstanding scientific merit, such as:

  • General relativity: theoretical, mathematical, numerical, or experimental, including, but not restricted to, black holes, gravitational radiation, and multimessenger astrophysics.
  • Fluid mechanics: theoretical, mathematical, numerical, or experimental, including, but not restricted to, relativistic fluids far from equilibrium.
  • Evolution of partial differential equations related to fluids and gravity, including, but not restricted to, the geometric analysis of waves and fluids.
  • The physics and mathematics of neutron star mergers and high-energy nuclear collisions.

VandyGRAF Fall Seminar Series

All VandyGRAF talks will take place in SC 6333.


Michael Johnson, Harvard-Smithsonian

December 1, 1:00 pm

Black Hole Shadows and Photon Rings: Experimental Relativity with Radio Interferometry

By combining global networks of radio telescopes, very long baseline interferometry provides the sharpest images in astronomy. This technique has recently culminated in the first images of a black hole, produced using the Event Horizon Telescope (EHT). These images revealed dark “shadows” encircled by bright and unresolved rings for the nuclear supermassive black holes in M87 and the Milky Way. I will discuss these results, including their implications for astrophysical theories of black hole accretion and jet formation. I will then describe our efforts to develop the next-generation EHT (ngEHT) and a space-enhanced EHT over the coming decade, which will improve the dynamic range of current EHT images by two orders of magnitude and will enable studies of horizon-scale dynamics through black hole movies. These efforts can resolve the fractal substructure from unstable photon orbits near a black hole that is predicted to appear within the blurry EHT ring, and they will ultimately measure the masses of thousands of supermassive black holes across cosmic history.


Daniel Kapec, Harvard University

December 8, 1:00 pm


Jorge Noronha, UIUC

January 12, 1:00 pm


Sam Gralla, University of Arizona

January 19, 1:00 pm


Marcelo Disconzi, Vanderbilt University

January 26, 1:00 pm


Christopher Monahan, William and Mary

February 2, 1:00 pm


Veronica Dexheimer, Kent State University

February 9, 1:00 pm

Exotic Matter in Neutron Stars

The high densities achieved in neutron stars and the high densities and temperatures achieved in neutron-star mergers create ideal testing grounds in which to learn about exotic matter, namely hyperons and deconfined quarks. The presence of exotic matter can strongly affect the interior of neutron stars, but cannot be directly observed. New electromagnetic and gravitational-wave constraints have been slowly constraining the dense QCD equation of state, allowing us to learn important information about the strong interaction. Nevertheless, strong constraints on dense and hot matter depend on (a) the not yet observed post-merger period of gravitational-wave production from neutron-star mergers and (b) non-trivial comparisons with particle collision experimental data. In this talk, I discuss where we stand and what we expect to learn about dense matter in the near future.


Lorenzo Gavassino, Vanderbilt University

February 16, 1:00 pm


Robert Scherrer, Vanderbilt University

February 23, 1:00 pm


Bill Press, UT Austin

March 2, 1:00 pm


James Dent, ULL

March 9, 1:00 pm


Andrew Strominger, Harvard University

March 23, 1:00 pm


Edgar Shaghoulian, University of Pennsylvania

March 30, 1:00 pm


Alejandro Cardenas-Avendano, Princeton University

April 6, 1:00 pm


Charles Gale, McGill University

April 13, 1:00 pm


Mark Trodden, University of Pennsylvania

April 20, 1:00 pm


Frans Pretorius, Princeton University

April 27, 1:00 pm