Unweighted Hardy Inequalities on the Heisenberg Group and in Step-Two Carnot Groups

This paper establishes unweighted Hardy-type inequalities on step-two Carnot groups with one-dimensional vertical layers by employing a quantitative integration-by-parts mechanism that substitutes the non-horizontal Euler vector field with a controlled horizontal one, yielding explicit optimal constant bounds for the Heisenberg group and generalized non-isotropic structures.

Lorenzo d'Arca, Luca Fanelli, Valentina Franceschi + 1 more2026-03-05🔢 math

Localized locally convex topologies

This paper investigates the functional analytic properties of "localized" locally convex topologies TC\mathcal{T}_{\mathcal{C}} to characterize distributions arising as divergences of vector fields, demonstrating that while these topologies are sequential, they generally lack standard properties like being Fréchet-Urysohn or barrelled, and establishing a semireflexivity condition that yields a general existence theorem for solving div(v)=F\mathrm{div}(v) = F.

Thierry De Pauw2026-03-05🔢 math

Bounded Multilinear Functionals and Multicontinuous Functions on n-Normed Spaces

This paper introduces and establishes the equivalence of various notions of boundedness and continuity for multilinear functionals and functions on n-normed spaces, demonstrating that these concepts yield identical dual spaces with equivalent norms while providing illustrative examples and exploring the relationship between bounded multilinear functionals and multicontinuous functions.

Harmanus Batkunde, Muh. Nur, Al Azhary Masta + 1 more2026-03-05🔢 math

Order-Preserving Extensions of Hadamard Space-Valued Lipschitz Maps

This paper demonstrates that while order-preserving Lipschitz maps from subsets of one-dimensional partially ordered Hilbert spaces into Hadamard posets can always be extended without increasing the Lipschitz constant, such extensions are generally impossible in higher dimensions unless the order on the domain is trivial, thereby proving that no order-theoretic generalization of Kirszbraun's theorem exists.

Edoardo Gargiulo Efe A. Ok2026-03-05🔢 math

Some Plancherel identities for unbounded subsets of R\mathbb R in duality

This paper establishes Plancherel-type identities and proves the surjectivity of the Fourier transform for certain unbounded dual tiling sets in R\mathbb{R}, demonstrating that an open set tiles the real line by the finite set {0,1,,p1}\{0,1,\dots,p-1\} if and only if it admits a spectrum given by the Lebesgue measure on [12p,12p]+Z\left[-\tfrac{1}{2p}, \tfrac{1}{2p}\right] + \mathbb{Z}.

Piyali Chakraborty, Dorin Ervin Dutkay2026-03-05🔢 math

On well-posedness for parabolic Cauchy problems of Lions type with rough initial data

This paper establishes a comprehensive well-posedness theory for parabolic Cauchy problems with time-independent, uniformly elliptic, bounded measurable complex coefficients, demonstrating that tempered distributions in homogeneous Hardy–Sobolev or Besov spaces serve as valid initial data for weak solutions with gradients in weighted tent spaces when source terms are of Lions' type.

Pascal Auscher, Hedong Hou2026-03-05🔢 math