Notes on Tachyon Effective Actions and Veneziano Amplitudes

TL;DR

This paper reviews how tachyonic Dirac-Born-Infeld actions derived from open string theory can reproduce Veneziano amplitudes, highlighting their key properties and discussing potential extensions and open problems.

Contribution

It clarifies the connection between tachyon effective actions and Veneziano amplitudes, emphasizing a generalized limit of open string theory.

Findings

Tachyonic DBI actions reproduce Veneziano amplitudes in specific kinematic regions.

The construction extends the usual massless DBI limit to include tachyonic modes.

Open problems and potential extensions of the framework are discussed.

Abstract

In a previous paper (hep-th/0304045) it has been argued that tachyonic Dirac-Born-Infeld (DBI) actions can be obtained from open string theory in a limit, which generalizes the usual massless DBI limit. In the present note we review this construction focusing on a key property of the proposed tachyon effective actions: how they reproduce appropriate Veneziano amplitudes in a suitably defined kinematical region. Possible extensions and interesting open problems are briefly discussed.