# The 34th International Symposium on Lattice Field Theory (Lattice 2016)

24-30 July 2016
Highfield Campus, University of Southampton
Europe/London timezone

## O(3) model with Nienhuis action

26 Jul 2016, 15:20
20m
Building 67 Room 1003 (Highfield Campus, University of Southampton)

### Building 67 Room 1003

#### Highfield Campus, University of Southampton

Talk Theoretical Developments

### Speaker

Prof. Ulli Wolff (HU Berlin)

### Description

We study the O(3) sigma model on a D=2 lattice with a Boltzmann weight linearized in $\beta$ on each link. While the spin formulation now suffers from a sign-problem the equivalent loop model remains positive and becomes particularly simple. By studying the transfer matrix and by performing MC simulations in the loop form we study the mass gap coupling in a step scaling analysis. The question addressed is, whether or not such a simplified action still has the right universal continuum limit. If the answer is affirmative this would be helpful in widening the applicability of worm algorithm methods.

### Primary author

Prof. Ulli Wolff (HU Berlin)

### Co-author

Dr Ferenc Niedermayer (Bern University)

 Slides