Light sterile neutrinos

TL;DR

This review discusses the theoretical framework, experimental anomalies, and cosmological implications of light sterile neutrinos at the eV scale, highlighting their potential role in short-baseline oscillations and future research directions.

Contribution

It provides a comprehensive overview of the current status, global fits, and implications of light sterile neutrinos, integrating experimental, phenomenological, and cosmological perspectives.

Findings

Anomalies suggest short-baseline oscillations involving sterile neutrinos.

Global fits support the existence of light sterile neutrinos in 3+1 and 3+2 models.

Cosmological data impose constraints on sterile neutrino properties.

Abstract

The theory and phenomenology of light sterile neutrinos at the eV mass scale is reviewed. The reactor, Gallium and LSND anomalies are briefly described and interpreted as indications of the existence of short-baseline oscillations which require the existence of light sterile neutrinos. The global fits of short-baseline oscillation data in 3+1 and 3+2 schemes are discussed, together with the implications for beta-decay and neutrinoless double-beta decay. The cosmological effects of light sterile neutrinos are briefly reviewed and the implications of existing cosmological data are discussed. The review concludes with a summary of future perspectives.