Gyratonic pp-waves and their impulsive limit

TL;DR

This paper explores a class of exact gravitational pp-wave solutions representing spinning particles at light speed, analyzing their physical properties, impulsive limits, and geodesic behavior.

Contribution

It provides a detailed analysis of the off-diagonal metric components in spinning pp-waves, highlighting their physical and geometrical significance.

Findings

Identification of rotational frame dragging effects

Analysis of impulsive wave limits

Behavior of geodesics in spinning pp-waves

Abstract

We investigate a class of gravitational pp-waves which represent the exterior vacuum field of spinning particles moving with the speed of light. Such exact spacetimes are described by the original Brinkmann form of the pp-wave metric including the often neglected off-diagonal terms. We put emphasis on a clear physical and geometrical interpretation of these off-diagonal metric components. We explicitly analyze several new properties of these spacetimes associated with the spinning character of the source, such as rotational dragging of frames, geodesic deviation, impulsive limits and the corresponding behavior of geodesics.