FAUST Seminars - Fall 2013

(Monday 3:00 pm in SE 311)

Titles link to the slides or the abstracts.

Date Speaker Title
Sep 4 Rory Conboye Potentials for Transverse Trace-free Tensors
Sep 23 Atousa Shirazi (FAU) LQG propagator from the new spin foams
Sep 30 Shannon Ray (FAU) Isometric embedding of convex 2-surfaces in Euclidian 3-space
Oct 7 Xuping Wang (FAU) Parity in loop quantum gravity
Oct 21
9:00 AM
Petr Tsatsin (FAU) Binary Neutron Star Mergers: Simulations with arbitraryly spinning Stars.
Oct 28 Chris Tison (FAU) -- canceled --
Nov 4 Phillip Mendonca (FAU) -- canceled --
Nov 18 M.E. Hogan (FAU) Spinfoam cosmology for beginners
Nov 25 Gregory Shields (U. Texas at Austin) A Captured Runaway Black Hole in NGC 1277?

Seminar Abstracts

Potentials for Transverse Trace-free Tensors

Rory Conboye, Sep 4

In the initial conditions for 3+1 Numerical Relativity (ADM decomposition), transverse and trace-free (TT) tensors play a key role, generally representing two of the true degrees of freedom. However, finding an expression for a TT tensor depending on only two scalar functions is a non-trivial problem. Assuming either axial or translational symmetry, I will present a recent result, giving explicit expressions depending on two scalar functions alone, for all TT tensors in flat 3-space. This talk is based on joint work with Niall O'Murchadha (arXiv:1306.1363).

LQG propagator from the new spin foams

Atousa Shirazi, Sep 23

I will describe the development and basic concepts of the covariant, spinfoam formulation of quantum cosmology, also known as "spinfoam cosmology" (SFC). I will show that starting with the fully covariant path-integral formulation of quantum gravity known as the "spinfoam models", and under suitable assumptions and limits, one may recover the standard results of FLRW cosmology. This presentation will be primarily based on the original SFC paper by Bianchi, Rovelli, and Vidotto, "Towards Spinfoam Cosmology" (*Phys. Rev.* D*82*: 084035, 2010).

Spinfoam cosmology for beginners

M.E. Hogan, Nov 18

I will describe the development and basic concepts of the covariant, spinfoam formulation of quantum cosmology, also known as "spinfoam cosmology" (SFC). I will show that starting with the fully covariant path-integral formulation of quantum gravity known as the "spinfoam models", and under suitable assumptions and limits, one may recover the standard results of FLRW cosmology. This presentation will be primarily based on the original SFC paper by Bianchi, Rovelli, and Vidotto, "Towards Spinfoam Cosmology" (*Phys. Rev.* D*82*: 084035, 2010).

A Captured Runaway Black Hole in NGC 1277?

Gregory Shields , Nov 25

Recent results indicate that the compact lenticular galaxy NGC 1277 in the Perseus Cluster contains an ultra-massive black hole of 17 billion solar masses. This far exceeds the expected mass of the central black hole in a galaxy of the modest dimensions of NGC 1277. We suggest that this black hole was ejected from the nearby giant galaxy NGC 1275 and subsequently captured by NGC 1277. The ejection was the result of gravitational radiation recoil when two large black holes merged following the merger of two giant ellipticals that helped to form NGC 1275. The black hole wandered in the cluster core until it was captured in a close encounter with NGC 1277. The migration of black holes in clusters may be a common occurrence.