2024/11/18 by Stephan Dürr, Durr, Stephan, Philip Rouenhoff +1
Computer Science · Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Computational Geometry and Mesh Generation #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #Homotopy and Cohomology in Algebraic Topology
paper · pdf · doi:10.48550/arxiv.2411.11593
openalex publication_date 2024/11/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In two dimensions, U(Nc) gauge theories exhibit a non-trivial topological structure, while SU(Nc) theories are topologically trivial. Hence, for G = U(Nc) the phase space is divided into topological sectors, characterized by a topological index (a.k.a. ``topological charge''). These sectors are separated by action barriers, which diverge if the lattice spacing is taken small, resulting in an algorithmic problem known as ``topological freezing''. We study these theories in various box sizes and at various couplings. With the help of gradient flow we derive instanton-like solutions for 2D U(Nc) theory with a specific focus on the case of Nc = 2.