Some disquisitions on cosmological 2-form dualities

TL;DR

This paper explores the dualities of cosmological 2-form fields, demonstrating their compatibility with cosmological principles, analyzing dual descriptions of various models, and discussing their implications for cosmological phenomena and gravitational wave signatures.

Contribution

It provides explicit constructions of massless 2-forms compatible with cosmology and analyzes dualities in various models, including their role in effective field theories and gravitational wave predictions.

Findings

Massless 2-forms can be compatible with the cosmological principle.

Dual descriptions of models like DBI, cuscuton, and ghost condensate are analyzed.

Self-interacting 2-forms can describe solids, fluids, and superfluids in cosmology.

Abstract

In this work we study different aspect of self-interacting 2-form fields with special emphasis in their cosmological applications. We provide the explicit construction of how massless 2-forms are compatible with the cosmological principle without resorting to the dual scalar field formulation. In terms of the 2-form, the residual Euclidean group is non-trivially realised by means of a combination of external spatial translations and internal gauge transformations. After presenting the general discussion of the dualities in cosmological scenarios, we analyse particular examples for some singular models and discuss in some detail the dual descriptions of the DBI, the cuscuton and the ghost condensate as well as the role of the duality in the effective field theories of cosmological perturbations. We then proceed to analysing scenarios with several self-interacting massless 2-forms and we show that they naturally provide the dual description of a solid. We then show how the perfect fluid and superfluids can be obtained by taking the appropriate limits in the dual formulations. We finally consider the case of massive 2-forms and their duals and briefly discuss their potential signatures in gravitational waves astronomy.