Negative Energy Density in Calabi-Yau Compactifications

TL;DR

This paper demonstrates that many supersymmetric compactifications, including Calabi-Yau and G_2 manifolds, can have arbitrarily negative local energy densities, leading to potential physical instabilities despite positive total energy.

Contribution

It reveals the existence of unbounded negative energy densities in classical supersymmetric compactifications, challenging previous assumptions about their stability.

Findings

Negative energy densities are unbounded from below in these compactifications.

Total ADM energy remains positive despite local negative densities.

Potential implications include thermal instabilities and violations of cosmic censorship.

Abstract

We show that a large class of supersymmetric compactifications, including all simply connected Calabi-Yau and G_2 manifolds, have classical configurations with negative energy density as seen from four dimensions. In fact, the energy density can be arbitrarily negative -- it is unbounded from below. Nevertheless, positive energy theorems show that the total ADM energy remains positive. Physical consequences of the negative energy density include new thermal instabilities, and possible violations of cosmic censorship.