The Cosmological Model with a Wormhole and Hawking Temperature near Apparent Horizon

TL;DR

This paper derives an exact cosmological model with a Morris-Thorne type wormhole embedded in an expanding universe, analyzes its horizons and causal structure, and calculates the Hawking temperature near the apparent horizon.

Contribution

It presents a novel exact solution for a wormhole in a Friedmann-Lemaître-Robertson-Walker universe and analyzes its thermodynamic properties.

Findings

Exact solution for wormhole in expanding universe

Identification of apparent cosmological horizons

Calculation of Hawking temperature near horizon

Abstract

In this paper, a cosmological model with an isotropic form of the Morris-Thorne type wormhole was derived in a similar way to the McVittie solution to the black hole in the expanding universe. By solving Einstein's field equation with plausible matter distribution, we found the exact solution of the wormhole embedded in Friedmann-Lema\^{\i}tre-Robertson-Walker universe. We also found the apparent cosmological horizons from the redefined metric and analyzed the geometric natures, including causal and dynamic structures. The Hawking temperature for thermal radiation was obtained by the WKB approximation using the Hamilton-Jacobi equation and Hamilton's equation, near the apparent cosmological horizon.