Gravitational lensing of transient neutrino sources by black holes

TL;DR

This paper investigates how Schwarzschild black holes gravitationally lens transient neutrino sources, revealing that multiple images with time delays could be detected separately, aiding identification despite current instrument limitations.

Contribution

It provides a detailed analysis of neutrino lensing by black holes, highlighting the potential for detecting multiple images through time delays with future detectors.

Findings

Primary and secondary images have angular separations beyond future detector resolution.

Time delays between images are longer than typical event durations.

Relativistic images are too faint for next-generation instrument detection.

Abstract

In this work we study gravitational lensing of neutrinos by Schwarzschild black holes. In particular, we analyze the case of a neutrino transient source associated with a gamma-ray burst lensed by a supermassive black hole located at the center of an interposed galaxy. We show that the primary and secondary images have an angular separation beyond the resolution of forthcoming km-scale detectors, but the signals from each image have time delays between them that in most cases are longer than the typical duration of the intrinsic events. In this way, the signal from different images can be detected as separate events coming from the very same location in the sky. This would render an event that otherwise might have had a low signal-to-noise ratio a clear detection, since the probability of a repetition of a signal from the same direction is negligible. The relativistic images are so faint and proximate that are beyond the sensitivity and resolution of the next-generation instruments.