Schild's Null Strings in Flat and Curved Backgrounds

TL;DR

This paper explores null (tensionless) string configurations in flat and curved spacetimes, identifying stationary solutions on horizons and providing a method to find such strings in various cosmological backgrounds.

Contribution

It introduces a general approach for constructing null string solutions in diverse backgrounds, including explicit examples in Schwarzschild, Rindler, and cosmological spacetimes.

Findings

Stationary null strings on horizons of Schwarzschild and Rindler spacetimes

A dynamic null string in Rindler spacetime

A general prescription for null string configurations in cosmological backgrounds

Abstract

Schild's null (tensionless) strings are discussed in certain flat and curved backgrounds. We find closed, stationary, null strings as natural configurations existing on the horizons of spacetimes which possess such null hypersurfaces. Examples of these are obtained in Schwarzschild and Rindler spacetimes. A dynamic null string is also identified in Rindler spacetime. Furthermore, a general prescription (with explicit examples) is outlined by means of which null string configurations can be obtained in a large class of cosmological backgrounds.