Conformal invariance, supersymmetry and string theory

Conformal Invariance, Supersymmetry and String Theory

Covariant quantization of string theories is developed in the context of conformal field theory and the BRST quantization procedure. The BRST method is used to covariantly quantize superstrings, and in particular to construct the vertex operators for string emission as well as the supersymmetry charge. The calculation of string loop diagrams is sketched. We discuss how conformal methods can be ...

1. Supersymmetry and String Theory

String Theory, Unification and Supersymmetry

One cannot yet point to any firm string prediction. While many approximate string ground states are known with interesting properties, we do not have any argument that one or another describes what we observe around us, and for reasons which appear fundamental we do not know how to systematically determine even any rough quantitative properties. I argue here that we should examine large classes...

Splitting Supersymmetry in String Theory

We point out that type I string theory in the presence of internal magnetic fields provides a concrete realization of split supersymmetry. To lowest order, gauginos are massless while squarks and sleptons are superheavy. We build such realistic U(3) × U(2) × U(1) models on stacks of magnetized D9-branes. Though not unified into a simple group, these theories preserve the successful supersymmetr...

String Theory Origins of Supersymmetry

The string theory introduced in early 1971 by Ramond, Neveu, and myself has two-dimensional world-sheet supersymmetry. This theory, developed at about the same time that Golfand and Likhtman constructed the four-dimensional super-Poincaré algebra, motivated Wess and Zumino to construct supersymmetric field theories in four dimensions. Gliozzi, Scherk, and Olive conjectured the spacetime supersy...