Renormalisation of non-differentiable potentials

TL;DR

This paper investigates how quantum fluctuations influence the renormalisation of non-differentiable potentials, demonstrating their smoothing effect and exploring applications in brane models and O(N) scalar field theories.

Contribution

It applies the Exact Wilsonian Renormalisation approach to non-differentiable potentials, revealing how quantum effects smooth out singularities and extending analysis to various physical models.

Findings

Quantum fluctuations smoothen the singularities of non-differentiable potentials.

Renormalisation modifies the shape of potentials in brane and scalar field models.

Applications include effective branon potentials and O(N) models in different dimensions.

Abstract

Non-differentiable potentials, such as the V-shaped (linear) potential, appear in various areas of physics. For example, the effective action for branons in the framework of the brane world scenario contains a Liouville-type interaction, i.e., an exponential of the V-shaped function. Another example is coming from particle physics when the standard model Higgs potential is replaced by a periodic self-interaction of an N-component scalar field which depends on the length, thus it is O(N) symmetric. We first compare classical and quantum dynamics near non-analytic points and discuss in this context the role of quantum fluctuations. We then study the renormalisation of such potentials, focusing on the Exact Wilsonian Renormalisation approach, and we discuss how quantum fluctuations smoothen the bare singularity of the potential. Applications of these results to the non-differentiable effective branon potential and to the O(N) models when the spatial dimension is varied and to the O(N) extension of the sine-Gordon model in (1+1) dimensions are presented.