Accretion flows around exotic tidal wormholes I. Ray-tracing

TL;DR

This study explores the properties of spherically symmetric tidal wormholes using ray-tracing and microlensing, revealing how accretion flows and shadows differ from black holes, and constraining wormhole parameters with observational data.

Contribution

It introduces a modified ray-tracing method for tidal wormholes and analyzes their accretion flows, photon spheres, and shadows, providing new insights into their observational signatures.

Findings

Photon sphere exists for Schwarzschild-like wormholes even with vanishing tidal forces.

Photon sphere radius increases with parameter , constrained by EHT observations.

Wormhole shadow size varies with parameters, affecting detectability.

Abstract

This paper investigates the various spherically symmetric wormhole solutions in the presence of tidal forces and applies numerous methods, such as test particle orbital dynamics, ray-tracing and microlensing. We make the theoretical predictions on the test particle orbital motion around the tidal wormholes with the use of normalized by $\mathcal{L}^2$ effective potential. In order to obtain the ray-tracing images (of both geometrically thin and thick accretion disks, relativistic jets), we properly modify the open source $\texttt{GYOTO}$ code with python interface. We applied this techniques to probe the accretion flows nearby the Schwarzschild-like and charged Reissner-N\"ordstrom (RS) wormholes (we assumed both charged RS wormhole and special case with the vanishing electromagnetic charge, namely Damour-Solodukhin (DS) wormhole). It was shown that the photon sphere for Schwarzschild-like wormhole presents for both thin and thick accretion disks and even for the vanishing tidal forces. Moreover, it was observed that $r_{\mathrm{ph}}\to\infty$ as $\alpha\to\infty$, which constraints $\alpha$ parameter to be sufficiently small and positive in order to respect the EHT observations. On the other hand, for the case of RS wormhole, photon sphere radius shrinks as $\Lambda\to\infty$, as it was predicted by the effective potential. In addition to the accretion disks, we as well probe the relativistic jets around two wormhole solutions of our consideration. Finally, with the help of star bulb microlensing, we approximate the radius of the wormhole shadow and as we found out, for Schild WH, $R_{\mathrm{Sh}}\approx r_0$ for ZTF and grows linearly with $\alpha$. On the contrary, shadow radius for charged wormholes slowly decreases with the growing trend of DS parameter $\Lambda$.