Rubio de Francia Extrapolation Theorem for Quasi non-increasing Sequences

This paper establishes the discrete Rubio de Francia extrapolation theorem for pairs of quasi non-increasing sequences with QBβ,p\mathcal{QB}_{\beta, p} weights and provides a weight characterization for the boundedness of the generalized discrete Hardy averaging operator on such sequences within the space lwp(Z+)l_w^p(\mathbb{Z}^+).

Monika Singh, Amiran Gogatishvili, Rahul Panchal, Arun Pal SinghMon, 09 Ma🔢 math

Weighted Sobolev Inequalities via the Meyers--Ziemer Framework: Measures, Isoperimetric Inequalities, and Endpoint Estimates

This paper establishes a new global endpoint Sobolev inequality for measures that extends the Meyers-Ziemer theorem by incorporating a maximal function, thereby unifying and advancing the understanding of weighted bounded variation, isoperimetric inequalities, and fractional operator estimates while identifying sharp conditions for non-endpoint cases.

Simon Bortz, Kabe Moen, Andrea Olivo + 2 more2026-03-06🔢 math

Uniqueness of the Canonical Reciprocal Cost

This paper proves that a function penalizing deviations from equilibrium is uniquely determined as the "canonical reciprocal cost" (the difference between arithmetic and geometric means of a ratio and its reciprocal) by combining a d'Alembert-type composition law with a single quadratic calibration, while also demonstrating the necessity of these assumptions for uniqueness and establishing stability properties.

Jonathan Washburn, Milan Zlatanović2026-03-06🔢 math

Catching jumps of metric-valued mappings with Lipschitz functions

This paper demonstrates that while a continuous map into a metric space is of bounded variation if and only if its composition with every Lipschitz function is of bounded variation, this characterization fails for discontinuous maps in spaces like 2\ell_2, infinite metric trees, and Laakso-type spaces, though it remains valid for ultrametric spaces without continuity assumptions.

Dmitriy Stolyarov, Alexander Tyulenev2026-03-05🔢 math

A degeneration of the generalized Zwegers' μμ-function according to the Ramanujan difference equation

This paper introduces the "little μ\mu-function" as a degenerate limit of Zwegers' generalized μ\mu-function, deriving it via qq-Borel summation of a divergent solution to the Ramanujan difference equation and establishing its key properties, including symmetries, connection formulas, and relations to q,tq,t-Fibonacci sequences and the Rogers-Ramanujan continued fraction.

G. Shibukawa, S. Tsuchimi2026-03-05🔢 math

On Hausdorff dimensions of kk-point configuration sets and Elekes-Rónyai type theorems

This paper establishes dimension expansion results for kk-point configuration sets generated by real analytic functions, proving that such sets attain positive Lebesgue measure or strictly larger Hausdorff dimensions under specific conditions by leveraging optimal L2L^2-based Sobolev estimates for Fourier integral operators and extending the Mattila-Sjölin and Falconer-type frameworks.

Minh-Quy Pham2026-03-05🔢 math