High Energy / Nuclear Theory / RIKEN seminars

[NT/RBRC seminar] Inverse renormalization group: Evading the critical slowing down effect

by Mr Dimitrios Bachtis (Swansea university)

US/Eastern
https://bnl.zoomgov.com/j/1610096044?pwd=Z2JVMmNsZXlGNjFtRmVENUwvSmRjdz09

https://bnl.zoomgov.com/j/1610096044?pwd=Z2JVMmNsZXlGNjFtRmVENUwvSmRjdz09

Description

The standard real-space renormalization group, which iteratively eliminates degrees of freedom in a system, is a powerful computational tool used to study efficiently phase transitions. However, the method manifests one limitation: it can only be applied for a finite number of steps before the degrees of freedom vanish. In this talk I will present the inverse renormalization group approach, which introduces degrees of freedom within a system and can therefore be applied for an arbitrary number of steps. Given configurations of the two-dimensional $\phi^{4}$ theory on lattice volumes as small as $V=8^{2}$, and without the need to conduct additional simulations, we will apply a set of inverse transformations to obtain lattices of volumes up to $V=512^{2}$. In absence of the critical slowing down effect we will then utilize the renormalized systems to accurately extract multiple critical exponents for the phase transition of the $\phi^{4}$ theory.