Extreme value theorem for geodesic flow on the quotient of the theta group

This paper establishes an extreme value theorem for the geodesic flow on the hyperbolic surface associated with the theta group by introducing a spliced continued fraction algorithm, proving its dynamical equivalence to the flow's first return map, and deriving a Galambos-type extreme value law for maximal cusp excursions via spectral analysis of the transfer operator.

Jaelin Kim, Seul Bee Lee, Seonhee Lim2026-03-10🔢 math

Group-Sparse Smoothing for Longitudinal Models with Time-Varying Coefficients

This paper proposes TV-Select, a unified framework that simultaneously identifies relevant variables and distinguishes between constant and time-varying effects in longitudinal models by employing a doubly penalized B-spline approach with group Lasso and roughness penalties to achieve accurate structural recovery, smooth estimation, and improved predictive performance.

Yu Lu, Tianni Zhang, Yuyao Wang, Mengfei Ran2026-03-10🔢 math

Rough differential equations driven by TFBM with Hurst index H(14,13)H\in (\frac{1}{4}, \frac{1}{3})

This paper establishes the existence and uniqueness of solutions to rough differential equations driven by tempered fractional Brownian motion with Hurst index H(14,13)H \in (\frac{1}{4}, \frac{1}{3}) by canonically lifting the noise to a geometric rough path and employing a Doss-Sussmann transformation combined with a greedy stopping time sequence, while also deriving quantitative growth bounds for the solutions.

Lijuan Zhang, Jianhua Huang2026-03-10🔢 math

Heterogeneous Stochastic Momentum ADMM for Distributed Nonconvex Composite Optimization

This paper proposes HSM-ADMM, a novel distributed stochastic algorithm for nonconvex composite optimization that achieves optimal O(ϵ1.5)\mathcal{O}(\epsilon^{-1.5}) complexity with a single-loop structure and minimal communication by employing node-specific adaptive step sizes to decouple convergence stability from global network properties.

Yangming Zhang, Yongyang Xiong, Jinming Xu, Keyou You, Yang Shi2026-03-10🔢 math

On an infinite sequence of strongly regular digraphs with parameters (9(2n+3),3(2n+3),2n+4,2n+1,2n+4)(9(2n+3), 3(2n+3), 2n+4, 2n+1, 2n+4)

This paper constructs and proves the existence of an infinite sequence of strongly regular digraphs with parameters (9(2n+3),3(2n+3),2n+4,2n+1,2n+4)(9(2n+3), 3(2n+3), 2n+4, 2n+1, 2n+4) by utilizing block circulant matrices, polynomial arithmetic, and computational tools to derive explicit adjacency formulas and propose a conjecture regarding their automorphism groups.

Viktor A. Byzov, Igor A. Pushkarev2026-03-10🔢 math

Low Mach Number Limit and Convergence Rates for a Compressible Two-Fluid Model with Algebraic Pressure Closure

This paper rigorously establishes the low Mach number limit and derives explicit convergence rates for a three-dimensional viscous compressible two-fluid model with algebraic pressure closure, proving that its well-prepared strong solutions converge to the incompressible Navier–Stokes equations as the Mach number tends to zero.

Yang Li, Mária Lukáčová-Medvidová, Ewelina Zatorska2026-03-10🔢 math

A low-dissipation central scheme for ideal MHD

This paper extends a low-dissipation central upwind scheme, originally developed for Euler equations, to the ideal magnetohydrodynamics (MHD) system by combining a cell-centered hydrodynamic solver with a face-based constrained transport method for magnetic fields, thereby achieving enhanced contact wave resolution, second-order accuracy, and machine-precision divergence-free magnetic fields in one and two dimensions.

Yu-Chen Cheng, Praveen Chandrashekar, Christian Klingenberg2026-03-10🔢 math

Positive isometric Fourier multipliers on non-commutative LpL^p-spaces

This paper characterizes positive surjective isometric Fourier multipliers on non-commutative LpL^p-spaces of a locally compact group for p2p \neq 2, proving that such operators arise if and only if their symbols are locally almost everywhere equal to continuous characters of the group, thereby extending previous results from the unimodular to the general setting.

Christoph Kriegler, Christian Le Merdy, Safoura Zadeh2026-03-10🔢 math