Swampland implications of GW170817-compatible Einstein-Gauss-Bonnet gravity

S.D Odintsov,V.K Oikonomou

doi:10.1016/j.physletb.2020.135437

S.D Odintsov, V.K Oikonomou

Open Access

https://doi.org/10.1016/j.physletb.2020.135437

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Abstract

We revisit the Einstein-Gauss-Bonnet theory in view of the GW170817 event, which compels that the gravitational wave speed is equal to cT2=1 in natural units. We use an alternative approach compared to one previous work of ours, which enables us to express all the slow-roll indices and the observational indices as functions of the scalar field. Using our formalism we investigate if the Swampland criteria are satisfied for the Einstein-Gauss-Bonnet theory and as we demonstrate, the Swampland criteria are satisfied for quite general forms of the potential and the Gauss-Bonnet coupling function ξ(ϕ), if the slow-roll conditions are assumed to hold true.

Highlights

The gravitational wave detection coming from the neutron star merging GW170817 event [1], has utterly affected modified theories of gravity, excluding some of these from being viable descriptions of our Universe at astrophysical scales
The gravitational wave speed is given in Eq (1), so by requiring that this is equal to c2T = 1, this implies that the Gauss-Bonnet scalar coupling function must satisfy the differential equation ξ −
1 can be related to any phenomenologically viable Einstein-Gauss-Bonnet theory compatible with the GW170817 event, and as we show in Ref. [72], it proves that the condition √ξ

Summary

Introduction

The gravitational wave detection coming from the neutron star merging GW170817 event [1], has utterly affected modified theories of gravity, excluding some of these from being viable descriptions of our Universe at astrophysical scales. The gravitational wave speed for an Einstein-Gauss-Bonnet theory is equal to, c2T The result of this letter in short is that the Swampland criteria for Einstein-Gauss-Bonnet theories of gravity can be satisfied for general within assumptions scalar coupling function ξ(φ) and scalar field potential V (φ).

Results

Conclusion