This paper is devoted to recent progress made towards the understanding of closed bosonic
and fermionic string perturbation theory, formulated in a Lorentz-covariant way on Euclidean …

We review recent developments in the construction of heterotic and type II string field
theories and their various applications. These include systematic procedures for determining …

We discuss superstring models with spontaneous breaking of N= 1, 2 or 4 space-time
supersymmetry, via coordinate-dependent compactifications from five to four dimensions …

A ten-dimensional super-Poincaré covariant formalism for the superstring was recently
developed which involves a BRST operator constructed from superspace matter variables …

We present an account of string field theory which aims to introduce the reader to the
important concepts of the subjects as well as to aid access to the literature. Light cone string …

An unambiguous and slice-independent formula for the two-loop superstring measure on
moduli space for even spin structure is constructed from first principles. The construction …

The N-point amplitudes for the type II and heterotic superstrings at two-loop order and for N⩽
4 massless NS bosons are evaluated explicitly from first principles, using the method of …

Computing the renormalized masses and S‐matrix elements in string theory, involving states
whose masses are not protected from quantum corrections, requires defining off‐shell …

Vacuum energy cancellation in a nonsupersymmetric string Page 1 Vacuum energy
cancellation in a nonsupersymmetric string Shamit Kachru Department of Physics …

A detailed derivation from first principles is given for the unambiguous and slice-
independent formula for the two-loop superstring chiral measure which was announced in …