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

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

Steady States of Transport-Coagulation-Nucleation Models

This paper establishes the existence and qualitative properties of steady states for a nonlinear integro-differential equation modeling polymer dynamics involving nucleation, transport, and multiplicative coagulation, demonstrating that a sufficiently strong decay rate for large polymers prevents gelation despite the coagulation kernel's tendency to cause it in isolation.

Julia Delacour, Marie Doumic, Carmela Moschella, Christian SchmeiserWed, 11 Ma🔢 math

Transformed p\ell_p Minimization Model and Sparse Signal Recovery

This paper introduces a flexible transformed p\ell_p minimization model with two adjustable parameters to enhance sparse signal recovery, establishing exact and stable recovery guarantees via the restricted isometry property, proposing an efficient IRLSTLp algorithm with convergence proofs, and demonstrating its superior performance and theoretical bounds through numerical experiments.

Ziwei Li, Wengu Chen, Huanmin Ge, Dachun YangWed, 11 Ma🔢 math

The Flint Hills Series, Mixed Tate Motives, and a Criterion for the Irrationality Measure of π\pi

This paper establishes that the convergence of the Flint Hills series is equivalent to the irrationality measure of π\pi being at most $5/2,andconditionallyonthisbound,identifiestheseriesasaperiodofaMixedTateMotiveyieldingaconjecturalclosedforminvolving, and conditionally on this bound, identifies the series as a period of a Mixed Tate Motive yielding a conjectural closed form involving \zeta(3)and and L(3, \chi_{-3})$.

Carlos Lopez ZapataWed, 11 Ma🔢 math

Locally 0\aleph_0-categorical theories and locally Roelcke precompact groups

This paper extends the correspondence between automorphism groups and 0\aleph_0-categorical structures to the locally Roelcke precompact and locally 0\aleph_0-categorical settings by defining the latter, proving a Ryll-Nardzewski theorem, characterizing the associated groups via isometric actions, and establishing that bi-interpretability of structures is equivalent to the isomorphism of their automorphism groups.

Itaï Ben Yaacov, Todor TsankovWed, 11 Ma🔢 math

(λ+)(\lambda^+)-injective Banach spaces

This paper resolves the open case for λ>2\lambda > 2 in Pelczyński's theorem by constructing (λ+)(\lambda^+)-injective but not λ\lambda-injective Banach spaces via an iterative "zero-sum" subspace technique, while also establishing a new upper bound of $9+6\sqrt{3}fortheBanachMazurdistancebetween for the Banach-Mazur distance between L_\infty[0,1]and and \ell_\infty$.

Tomasz Kania, Grzegorz LewickiWed, 11 Ma🔢 math

ACS Condition on Minimal Isoparametric Hypersurfaces of Positive Ricci Curvature in Unit Spheres

Motivated by the Schoen–Marques–Neves conjecture, this paper verifies a sufficient pointwise Ambrozio–Carlotto–Sharp inequality for minimal isoparametric hypersurfaces with positive Ricci curvature in unit spheres, thereby establishing a lower bound on the Morse index proportional to the first Betti number for closed embedded minimal hypersurfaces in these ambient manifolds.

Niang ChenWed, 11 Ma🔢 math