Effective action and tension renormalization for cosmic and fundamental strings

TL;DR

This paper derives an effective action for classical strings interacting with various fields, clarifying tension renormalization, divergence handling, and limitations of traditional energy-based approaches, with implications for cosmic and fundamental strings.

Contribution

It introduces a comprehensive effective action framework for string-field interactions, elucidating renormalization and divergence issues specific to cosmic and fundamental strings.

Findings

Renormalization of string tension using the effective action.

Linking ultraviolet divergences to long-range interactions.

Highlighting limitations of Dirac's energy approach in string renormalization.

Abstract

We derive the effective action for classical strings coupled to dilatonic, gravitational, and axionic fields. We show how to use this effective action for: (i) renormalizing the string tension, (ii) linking ultraviolet divergences to the infrared (long-range) interaction between strings, (iii) bringing additional light on the special cancellations that occur for fundamental strings, and (iv) pointing out the limitations of Dirac's celebrated field-energy approach to renormalization.