I have a new paper out on Lovelock gravity. It is well known that ordinary gravity in D=3 is almost, but not quite, trivial. The underlying reason for this is a curvature identity in D=3 that allows the Riemann tensor to be expressed in terms of its traces, the Ricci tensor and scalar curvature. These, [...]
Sourya Ray completed his PhD at UMass under the supervision of Jennie Traschen and myself in 2008. After graduating, Sourya moved on to a postdoctoral research position with the excellent gravity theory group at the Centro de Estudios Cientificos (CECs) in Valdivia, Chile. This went quite well and I’m happy to report that Sourya has [...]
I am happy to be serving for this academic year as Interim Director of the BDIC Program. BDIC (stands for Bachelor’s Degree with Individualized Concentration) is a program that allows UMass undergraduates to design their own individualized, interdisciplinary majors. Roughly 80-100 BDIC students graduate each year with concentrations spread all over the academic map (and [...]
It has been known since the 1980′s that black strings are unstable to long wavelength perturbations. However, it is difficult to establish what the end point of this instability is. Similarly, it is expected that for Kaluza-Klein black holes – e.g. where one spacetime dimension is wrapped around a circle – that there would be [...]
Jennie Traschen, Sourya Ray and I posted a new paper – The Mass and Free Energy of Lovelock Black Holes – recently. Static Lovelock black holes can be thought of as “semi-unknown” solutions. The metric functions are known in terms of solutions to a polynomial equation of order [D-1/2], where D is the spacetime dimension [...]
UMass graduate student Ben Ett and I recently submitted a paper with the above title to the arXiv. The basic idea is the following. Lovelock gravity is a natural higher derivative extension of Einstein gravity in higher dimensions. Static Lovelock black hole solutions have been known since the 1980′s and have appeared in many different [...]
My HEP bag lunch talk on March 8th this semester was a very speculative one, exploring possible connections between cosmic censorship and computational complexity theory. The basic idea is that extreme spacetimes, such as those with naked singularities or perhaps those with closed timelike curves, may offer special computational amenities. Perhaps the boundaries between computational [...]
The AdS/CFT conjecture relates a quantum field theory in a given dimension to gravitational physics in one dimension higher. Strong coupling QFT phenomena can be descried by classical general relativity. My bag lunch talk on “holographic superconductors” is an introduction to approaches to extending AdS/CFT to systems relevant in condensed matter physics. Holographic Superconductor talk
The GR19 was held in Mexico City in July, 2010. I spoke about my recent work with Jennie Traschen and Sourya Ray limited to the Einstein-AdS case (which was enough to try to get through in 20 minutes). GR19 talk
Jennie Traschen, Sourya Ray and I have written a number of papers (here, here and here) in the past few years looking at certain types of black hole thermodynamic relations – Smarr formulas and related extensions of the first law – in a wider class of theories.
