collaborators

7 papers

math.AP2026

The Hardy averaging operator between Orlicz spaces and a new gauge functional characterizing a given Orlicz space

Amiran Gogatishvili, Ron Kerman, Susanna Spektor

We prove that the largest Orlicz space into which the Hardy averaging operator maps coincides with the largest rearrangement-invariant (r.i.) space mapping into that space; in othe…

math.MG2026

Quantitative stability of the intersection body operator near the ball, and the dynamical origin of the two--dimensional degeneracy

S. Spektor

Let $\IB$ denote the intersection body operator on star bodies in . A recent theorem of Milman, Shabelman and Yehudayoff establishes that for the equation $\IB^2 K =…

math.PR2026

Two Multi--Draw Coupon Collector models with different retention rules

Aristides V. Doumas, S. Spektor

In this paper we study two variants of the generalized coupon collector's problem, where our collector receives at each run d distinct coupons and keeps all the new observed coupon…

math.PR2026

Equal probabilities maximize the expected deficit in the siblings of the coupon collector

Aristides V. Doumas, S. Spektor

In the siblings (or brotherhood) variant of the coupon collector's problem, a main collector draws coupons until her own album is complete and passes every duplicate down a chain o…

math.ST2026

Kolmogorov-Type Maximal Inequalities for Independent and Dependent Negative Binomial Random Variables: Sharp Bounds, Sub-Exponential Refinements, and Applications to Overdispersed Count Data

Aristides V. Doumas, S. Spektor

This paper develops Kolmogorov-type maximal inequalities for sums of Negative Binomial random variables under both independence and dependence structures. For independent heterogen…

math.FA2026

Boundedness of Positive Integral Operators on Lorentz-Gamma Spaces

R. Kerman, S. Spektor

We characterize the boundedness of a positive integral operator , with kernel , between Lorentz-Gamma spaces and , $1…