A Cosmological Constant That is Too Small

Abstract

We construct a vacuum of string theory in which the magnitude of the vacuum energy is $<10^{-123}$ in Planck units. Regrettably, the sign of the vacuum energy is negative, and some supersymmetry remains unbroken.

Comments: 6 pages. A more detailed analysis appears in our companion paper 2107.09064. v2: typo fixed, results unchanged; approximately matches version published in PRL