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Title: Nonlinear sigma models with compact hyperbolic target spaces

We explore the phase structure of nonlinear sigma models with target spaces corresponding to compact quotients of hyperbolic space, focusing on the case of a hyperbolic genus-2 Riemann surface. The continuum theory of these models can be approximated by a lattice spin system which we simulate using Monte Carlo methods. The target space possesses interesting geometric and topological properties which are reflected in novel features of the sigma model. In particular, we observe a topological phase transition at a critical temperature, above which vortices proliferate, reminiscent of the Kosterlitz-Thouless phase transition in the O(2) model [1, 2]. Unlike in the O(2) case, there are many different types of vortices, suggesting a possible analogy to the Hagedorn treatment of statistical mechanics of a proliferating number of hadron species. Below the critical temperature the spins cluster around six special points in the target space known as Weierstrass points. In conclusion, the diversity of compact hyperbolic manifolds suggests that our model is only the simplest example of a broad class of statistical mechanical models whose main features can be understood essentially in geometric terms.
 [1] ;  [2] ;  [3] ;  [4] ;  [3]
  1. Princeton Univ., Princeton, NJ (United States)
  2. Univ. of Pennsylvania, Philadelphia, PA (United States); Quaid-e-Azam Univ. Campus, Islambad (Pakistan)
  3. Univ. of Pennsylvania, Philadelphia, PA (United States)
  4. California Inst. of Technology (CalTech), Pasadena, CA (United States)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
AC02-76ER03071; FG02-05ER46199; SC0011632
Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2016; Journal Issue: 6; Journal ID: ISSN 1029-8479
Springer Berlin
Research Org:
Univ. of Pennsylvania, Philadelphia, PA (United States); California Inst. of Technology, Pasadena, CA (United States)
Sponsoring Org:
Country of Publication:
United States
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS Effective field theories; Integrable Field Theories; Lattice Quantum Field Theory; Matrix Model