# Search for the Footprints of New Physics with Laboratory and Cosmic Neutrinos

## TL;DR

This paper reviews how high-energy neutrino observations can test for Lorentz invariance violation, potentially revealing effects of quantum gravity, by analyzing observational consequences of LIV terms in effective field theory.

## Contribution

It introduces a framework for testing Lorentz invariance violation using neutrino data and constrains non-renormalizable LIV operators linked to quantum gravity.

## Key findings

- Limits placed on Lorentz invariance violating operators
- Constraints on quantum gravity effects from neutrino observations
- Effective field theory formalism applied to LIV testing

## Abstract

Observations of high energy neutrinos, both in the laboratory and from cosmic sources, can be a useful probe in searching for new physics. Such observations can provide sensitive tests of Lorentz invariance violation (LIV), which may be a the result of quantum gravity physics (QG). We review some observationally testable consequences of LIV using effective field theory (EFT) formalism. To do this, one can postulate the existence of additional small LIV terms in free particle Lagrangians, suppressed by powers of the Planck mass. The observational consequences of such terms are then examined. In particular, one can place limits on a class of non-renormalizable, mass dimension five and six Lorentz invariance violating operators that may be the result of QG.