Propagation of Gravitational Waves in a Dynamical Wormhole Background for Two-scalar Einstein-Gauss-Bonnet Theory

TL;DR

This paper develops a model of Einstein-Gauss-Bonnet gravity with two scalar fields, demonstrating stable dynamical wormhole solutions and analyzing how gravitational waves propagate through these wormholes, revealing deviations from light speed.

Contribution

It introduces a novel two-scalar Einstein-Gauss-Bonnet model with constraints that allow stable, dynamical wormholes and studies gravitational wave propagation in this background.

Findings

Gravitational wave speed differs from light speed in the wormhole background.

The model supports stable, finite-time dynamical wormhole solutions.

Propagation speeds vary between incoming and outgoing gravitational waves.

Abstract

In this work, we propose a model of Einstein--Gauss-Bonnet gravity coupled with two scalar fields. The two scalar fields are considered to be ``frozen'' or they become non-dynamical by employing appropriate constraints in terms of Lagrange multiplier fields. We show that, even in the case that the arbitrary spherically symmetric spacetime is dynamical, we can construct a model where the wormhole spacetime is a stable solution in this framework. We especially concentrate on the model reproducing the dynamical wormhole, where the wormhole appears in a finite-time interval. We investigate the propagation of the gravitational wave in the wormhole spacetime background and we show that the propagation speed is different from that of light $\to$ light in general, and there is a difference in the speeds between the incoming propagating wave and the outgoing propagating gravitational wave.