Holographic constraint and effective field theories with N-species

TL;DR

This paper investigates constraints on the number of particle species in effective field theories with UV/IR mode mixing, using bounds from muon g-2 and gravitational considerations, impacting models with large N.

Contribution

It introduces a novel analysis of N-species effective field theories incorporating UV/IR mixing, applying muon g-2 and gravitational bounds to limit N.

Findings

Muon g-2 imposes a stronger bound on N than collider constraints.

Bound on N is approximately 10^{19} from muon g-2.

Large N theories cannot account for large entropy gaps near gravitational collapse.

Abstract

Effective field theories that manifest UV/IR mode mixing in such a way as to be valid for arbitrarily large volumes, can be used for gravitational, non-black hole events to be accounted for. In formulating such theories with a large number of particle species $N$, we employ constraints from the muon $g-2$, higher-dimensional operator corrections due to the required UV and IR cutoffs as well as the RG evolution in a conventional field-theoretical model in curved space. While in general our bounds on $N$ do reflect $N \simeq 10^{32}$, a bound motivated by the solution to the hierarchy problem in alike theories and obtained by the fact that strong gravity has not been seen in the particle collisions, the bound from the muon $g-2$ turns out to be much stronger, $N \lsim 10^{19}$. For systems on the verge of gravitational collapse, this bound on $N$ is far too restrictive to allow populating a large gap in entropy between those systems and that of black holes of the same size.