Vertical integration from the large Hilbert space

  title={Vertical integration from the large Hilbert space},
  author={Theodore G. Erler and Sebastian Konopka},
  journal={Journal of High Energy Physics},
A bstractWe develop an alternative description of the procedure of vertical integration based on the observation that amplitudes can be written in BRST exact form in the large Hilbert space. We relate this approach to the description of vertical integration given by Sen and Witten. 

On the Equivalence between SRS and PCO Formulations of Superstring Perturbation Theory

We establish the equivalence between two formulations of superstring perturbation theory, one based on integration over the supermoduli space of super Riemann surfaces (SRS), the other based on

Four lectures on closed string field theory

Background independence of closed superstring field theory

A bstractGiven a family of world-sheet superconformal field theories related by marginal deformation, we can formulate superstring field theory based on any of these world-sheet theories. Background

Mapping between Witten and lightcone string field theories

Abstract We propose a transformation between the off-shell field variables of Witten’s open bosonic string field theory and the traditional lightcone string field theory of Kaku and Kikkawa, based

Tree-level S-matrix of superstring field theory with homotopy algebra structure

We show that the tree-level S-matrices of the superstring field theories based on the homotopy-algebra structure agree with those obtained in the first-quantized formulation. The proof is given in

String Field Theory

  • H. Erbin
  • Physics
    Lecture Notes in Physics
  • 2021
This book provides an introduction to string field theory (SFT). String theory is usually formulated in the worldsheet formalism, which describes a single string (first-quantization). While this

Some Applications of Hyperbolic Geometry in String Perturbation Theory

In this thesis, we explore some applications of recent developments in the hyperbolic geometry of Riemann surfaces and moduli spaces thereof in string theory [1, 2, 3]. First we show how a proper

On the Existence of Heterotic-String and Type-II-Superstring Field Theory Vertices

We consider two problems associated to the space of Riemann surfaces that are closely related to string theory. We first consider the problem of existence of heterotic-string and type-II-superstring

Off‐Shell Amplitudes in String Theory and Hyperbolic Geometry

The construction of off‐shell amplitudes in closed string theory using Riemann surfaces having constant curvature −1 is explored in detail. Off‐shell string amplitudes constructed using surfaces with

Off-Shell Amplitudes



Multiloop calculations in covariant superstring theory

Closed superstring field theory and its applications

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 the shifts in the

NS-NS sector of closed superstring field theory

A bstractWe give a construction for a general class of vertices in superstring field theory which include integration over bosonic moduli as well as the required picture changing insertions. We apply

Resolving Witten’s superstring field theory

The replacement of the picturechanging insertion at the midpoint with a contour integral of picture changing insertions over the half-string overlaps of the cubic vertex creates an explicit covariant superstring field theory which by construction satisfies the classical BV master equation.

Filling the gaps with PCO’s

A bstractSuperstring perturbation theory is traditionally carried out by using picture-changing operators (PCO’s) to integrate over odd moduli. Naively the PCO’s can be inserted anywhere on a string

One loop tadpole in heterotic string field theory

A bstractWe compute the off-shell 1-loop tadpole amplitude in heterotic string field theory. With a special choice of cubic vertex, we show that this amplitude can be computed exactly. We obtain

Complete action for open superstring field theory

We construct a complete action for open superstring field theory that includes the NeveuSchwarz sector and the Ramond sector. For the Neveu-Schwarz sector, we use the string field in the large

Hyperbolic Geometry of Superstring Perturbation Theory

The hyperbolic structure of the RNS formulation of perturbative superstring theory is explored, with the goal of providing a systematic method for explicitly evaluating both the on-shell and the

Open superstring field theory based on the supermoduli space

A bstractWe present a new approach to formulating open superstring field theory based on the covering of the supermoduli space of super-Riemann surfaces and explicitly construct a gauge-invariant