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Abstract |
It has long been known that there exist strings with supersymmetry on the world
sheet, but not in spacetime. These include the well-known Type 0 strings, as well
as a series of seven heterotic strings, all of which are obtained by imposing
unconventional GSO projections. Besides these classic examples though, relatively
little is known about the full space of non-SUSY theories. One of the reasons why
non-SUSY strings have remained understudied is the fact that nearly all of them
have closed string tachyons, and hence do not admit ten-dimensional flat space as
a stable vacuum. The goal of this talk is two-fold. First, using recent advances
in condensed matter theory, we will reinterpret GSO projections in terms of
topological phases of matter, thereby providing a framework for the classification
of non-SUSY strings. Having done so, we will show that for all non-SUSY theories
in which a tachyon exists, it can be condensed to give a stable lower-dimensional
vacuum. In many cases, these stable vacua will be two-dimensional string theories
already known in the literature. |
