The unstable complex in Bruhat-Tits buildings for arithmetic groups over function fields

This paper establishes that for a principal congruence subgroup ΓGLr(K)\Gamma \subset GL_r(K) over a function field KK, the Γ\Gamma-unstable region of the Bruhat-Tits building for GLr(K)GL_r(K_\infty) is homotopy equivalent to the spherical Tits building for GLr(K)GL_r(K), extending Grayson's generalization of Serre's earlier result for GL2GL_2.

Gebhard Böckle, Sriram Chinthalagiri VenkataWed, 11 Ma🔢 math

Optimal Control in Age-Structured Populations: A Comparison of Rate-Control and Effort-Control

This paper contrasts the mathematical structures and optimality conditions of rate-control versus effort-control harvesting in age-structured populations, demonstrating how the multiplicative, aggregate-dependent nature of effort-control introduces nonlocal coupling in the adjoint system that fundamentally distinguishes it from the additive rate-control formulation.

Jiguang Yu, Louis Shuo WangWed, 11 Ma🔢 math

Rate-Distortion Bounds for Heterogeneous Random Fields on Finite Lattices

This paper establishes a finite-blocklength rate-distortion framework for heterogeneous random fields on finite lattices that explicitly incorporates tile-based processing constraints, providing non-asymptotic bounds and a second-order expansion to quantify the effects of spatial correlation, heterogeneity, and tile size on compression performance.

Sujata Sinha, Vishwas Rao, Robert Underwood, David Lenz, Sheng Di, Franck Cappello, Lingjia LiuWed, 11 Ma🔢 math

Finite-energy solutions to Einstein-scalar field Lichnerowicz equations on complete Riemannian manifolds

This paper establishes the existence and nonexistence of finite-energy solutions to singular Einstein-scalar field Lichnerowicz equations on complete Riemannian manifolds with low-regularity coefficients, utilizing ε\varepsilon-regularization, mountain pass arguments, and Harnack's inequality under specific spectral, geometric, and integrability conditions.

Bartosz Bieganowski, Pietro d'Avenia, Jacopo SchinoWed, 11 Ma🔢 math