Annual Meeting QGSKY - Quantum Universe

Does the cosmological constant really indicate the existence of a dark dimension?

6 Oct 2023, 12:20

20m

Aula Magna - Sede Storica UniGe via Balbi 5 (Genova)

Friday 11:40 - 13:20

Speaker

Arcangelo Pernace (Istituto Nazionale di Fisica Nucleare)

Description

When the Higgs effective potential $V_{eff}(\varphi )$ and/or the vacuum energy $\rho$ are derived from higher dimensional theories with compact extra dimensions and non-trivial boundary conditions (as in the case of the Scherk-Schwarz SUSY breaking mechanism), the usual calculations lead to the conclusion that these quantities are UV-insensitive. Based on the finite result for $\rho$ and on the measured value of the cosmological constant, it has been recently proposed that we might live in a universe with a single compact extra dimension (dark dimension), whose mesoscopic size is of order $\mu m$. Since this proposal has been advanced, a lot of work has been dedicated to studying several phenomenological consequences related to the existence of this fifth (compact) dimension. We show that a source of strong UV-sensitivity for $\rho$, intimately connected to the non-trivial topology of the spacetime, is missed by the usual calculation and renders the dark dimension proposal untenable, at least the way it has been originally formulated.

Presentation materials

Presentazione Pernace.pdf