The non-relativistic limit of HSZ Theory

TL;DR

This paper investigates the non-relativistic limit of HSZ theory, a higher-derivative gravity theory with T-duality, analyzing corrections and the structure of the theory in this limit, which relates to string theory truncations.

Contribution

It provides a detailed analysis of the non-relativistic limit of HSZ theory, including symmetry corrections and the behavior of higher-derivative terms, revealing new aspects of its structure.

Findings

Corrections to metric degrees of freedom cannot be fully trivialized in the NR limit.

The four-derivative terms depend on the b-field and are analyzed in detail.

Results relate to truncations of heterotic supergravity in the NR limit.

Abstract

We study the non-relativistic (NR) limit of HSZ theory, a higher-derivative theory of gravity with exact and manifest T-duality invariance. Since the theory can be formulated using the generalized metric formalism, the HSZ Lagrangian remains convergent to all orders in derivatives when taking the NR limit. In this work, we analyze the three-derivative corrections to the symmetry transformations of the fields in the NR case, as well as the terms in the four-derivative action depending on the b-field. Interestingly, the corrections to the metric degrees of freedom cannot be fully trivialized, as in the relativistic case, in order to preserve the convergence of the theory. As HSZ theory interpolates order by order between heterotic and bosonic string theories, the results of this work can be interpreted as a truncation of the four-derivative structure of heterotic supergravity in the NR limit.