Temperature versus acceleration: the Unruh effect for holographic models

TL;DR

This paper investigates how acceleration and velocity influence the perceived temperature in holographic models, revealing that acceleration enhances meson melting and that moving observers measure velocity-dependent temperatures, with implications for black hole backgrounds.

Contribution

It demonstrates that acceleration affects meson screening lengths and clarifies the origin of velocity-dependent temperatures in holographic models, providing new insights into Unruh effects in these settings.

Findings

Accelerated strings have smaller screening lengths than static ones at the same Unruh temperature.

Velocity dependence of screening length arises from observer motion in black hole backgrounds.

Accelerated particles in AdS black holes experience increasing temperature over time.

Abstract

We analyse the effect of velocity and acceleration on the temperature felt by particles and strings in backgrounds relevant in holographic models. First, we compare accelerated strings and strings at finite temperature. We find that for fixed Unruh temperature felt by the string endpoints, the screening length is smaller for the accelerated Wilson loop than for the static one in a thermal background of the same temperature; hence acceleration provides a "more efficient" mechanism for melting of mesons. Secondly, we show that the velocity-dependence of the screening length of the colour force, previously obtained from a moving Wilson loop in a finite temperature background, is not specific for the string, but is a consequence of the generic fact that an observer which moves with constant velocity in a black hole background measures a velocity-dependent temperature. Finally, we analyse accelerated particles and strings in the AdS black hole background, and show that these feel a temperature which increases as a function of time. As a byproduct of our analysis we find a global Minkowski embedding for the planar AdS black hole.