Theory HEP Seminar

E-string elliptic genus from domain walls

Guglielmo Lockhart

Harvard University

We study the six-dimensional conformal field theory of a small E8 instanton. This theory has a ‘tensor branch’, whose degrees of freedom are given by strings with small tension (E-strings). These strings can be realized in M-theory as M2 branes suspended between an M5 brane and a Horava-Witten M9 plane. We argue that the elliptic genus of multiple E-strings can be expressed in terms of combinations of ‘domain wall’ factors associated to the M5 and M9 boundaries. Following this approach, we obtain exact expressions for the elliptic genus of two E-strings. Furthermore, we show that the elliptic genus of two E8xE8 heterotic strings (M2 branes suspended between two M9 planes) can also be computed by taking appropriate combinations of two M9 factors.