13946666
A Quantum Mechanical Model of Spherical Supermembranes
We present a quantum mechanical model of spherical supermembranes. Using superfields to represent the cartesian coordinates of the membrane, we are able to exactly determine its supersymmetric vacua. We find there are two classical vacua, one corresponding to an extended membrane and one corresponding to a point-like membrane. For the = 2 case, instanton effects then lift these vacua to massive states. For the = 4 case, there is no instanton tunneling, and the vacua remain massless. Similarities to spherical supermembranes as giant gravitons and in Matrix theory on pp-waves is discussed.
7559823
Interactions of cosmic superstrings
We develop methods by which cosmic superstring interactions can be studied in detail. These include the reconnection probability and emission of radiation such as gravitons or small string loops. Loop corrections to these are discussed, as well as relationships to (p; q)-strings. These tools should allow a phenomenological study of string models in anticipation of upcoming experiments sensitive to cosmic string radiation.
3247660
Spin-statistics violations in superstring theory
I describe how superstring theory may violate spin statistics in an experimentally observable manner. Reviewing the basics of superstring interactions and how to utilize these to produce a statistical phase, I then apply these ideas to two specific examples. The first is the case of heterotic world sheet linkings, whereby one small closed string momentarily enlarges sufficiently to pass over another, producing such a statistical phase. The second is the braneworld model with noncommutative geometry, whereby matter composed of open strings may couple to a background in which spacetime coordinates do not commute, modifying the field (anti)commutator algebra. I conclude with ways to sharpen and experimentally test these exciting avenues to possibly verify superstring theory.
118351795
Balloon-borne hard X-ray astronomy with PoGOLite: Opening a new window on the universe
High energy polarization can be an indication of geometry, orientation, and other physical phenomena for a variety of sources, but has heretofore been a virtually unmeasured phenomenon. PoGOLite is a balloon-borne instrument intended to measure the polarization of X-rays between 25 and 100 keV. The pathfinder version of the instrument is scheduled to be launched from northern Sweden in summer 2013. The primary targets are the Crab pulsar and nebula and Cygnus X-1.