3 papers
cond-mat.stat-mech2026
Probing phase transitions of finite directed polymers near a corrugated wall via two-replica analysis
Ruijie Xu, Sergei Nechaev
We study the pinning transition in a (1+1)-dimensional lattice model of a fluctuating interface interacting with a corrugated impenetrable wall. The interface is modeled as an -…
math.CO2025
Integrability of Combinatorial Riemann Boundary Value Problem and Lattice Walks Avoiding a Quadrant
Ruijie Xu
We introduce a general framework of matrix-form combinatorial Riemann boundary value problem (cRBVP) to characterize the integrability of functional equations arising in lattice wa…
math.CO2025
Combinatorial Insight of Riemann Boundary Value Problem in Lattice Walk Problems
Ruijie Xu
The enumeration of quarter-plane lattice walks with small steps is a classical problem in combinatorics. An effective approach is the kernel method, where the solution is derived b…