Many statistical physics models are defined on an infinite lattice by taking appropriate limits of finite lattice regions, where a key consideration is how the boundaries are defined. For several models on planar lattices, such as 3-colorings and lozenge tilings, efficient sampling algorithms are known for regions with fixed boundary conditions, where the colors or tiles around the boundary are...

We study the Pöschl-Teller equation in complex domain and deduce infinite families of TQ and Bethe ansatz equations, classified by four integers. In all these models the form of T is very simple, while Q can be explicitly written in terms of the Heun function. At particular values there is a interesting interpretation in terms of finite lattice spin2 XXZ quantum chain with ∆ = cos π L (for free...

We consider a nonlocal boundary condition for anti-self-dual instantons on four-manifolds with a space-time splitting of the boundary. This boundary condition naturally arises from making the Chern-Simons functional on a three-manifold with boundary closed: The restriction of the instanton to each time-slice of the boundary is required to lie in a Lagrangian submanifold of the moduli space of f...

The theory of Riemann boundary value problem for analytic functions of one complex variable and singular integral equations that are equivalent to it has been extensively studied in the literature. For classical books on this topic see [7, 12, 13] and for an actual overview of them the reader is directed to the monograph by Estrada and Kanwal [6], and the references therein. In the more recent ...