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Amir Baghban

Publications and source records attributed to Amir Baghban.

6 recordsLinked to original sources
arXiv2025

Quantitative cyclicity, stability, and geometric analysis in weighted Besov spaces

We introduce new quantitative measures for cyclicity in radially weighted Besov spaces, including the Drury-Arveson space, by defining cyclicity indices based on potential theory and capacity. Extensions to non-commutative settings are developed, yielding analogues of cyclicity in free function spaces. We also study the stability of cyclic functions under perturbations of both the functions and the underlying weight, and we establish geometric criteria linking the structure of zero sets on the boundary to the failure or persistence of cyclicity. These results provide novel invariants and conditions that characterize cyclicity and the structure of multiplier invariant subspaces in a variety of function spaces.

math.FA↗
arXiv2025

Extremizers and Stability for Fractional $L^p$ Uncertainty Principles

We extend the classical Heisenberg uncertainty principle to a fractional $L^p$ setting by investigating a novel class of uncertainty inequalities derived from the fractional Schrödinger equation. In this work, we establish the existence of extremal functions for these inequalities, characterize their structure as fractional analogues of Gaussian functions, and determine the sharp constants involved. Moreover, we prove a quantitative stability result showing that functions nearly attaining the equality in the uncertainty inequality must be close -- in an appropriate norm -- to the set of extremizers. Our results provide new insights into the fractional analytic framework and have potential applications in the analysis of fractional partial differential equations.

math.CA↗
arXiv2022

A mathematical model for planning oil products distribution via pipeline

Compared to other transportation modes, road, railroad and vessel, multiproduct pipelines are the safest and most economical way of conveying petroleum products over long distances day and night. During the last two decades, the operational multiproduct pipeline scheduling has gained increasing attention, where most of the contributions are based on continuous time representation. In this paper, we present a new discrete-time mixed integer linear programming model for the shortterm scheduling of multiproduct pipelines featuring multiple refineries and distribution centers. The model optimally determines the sequence and planning of product injections at input nodes, the sequence of product deliveries to output nodes, and traces the size and the products location along the pipeline at any time. The proposed model also allows to execute simultaneous injections at the input nodes and to tackle simultaneous injections and deliveries at an intermediate node that can act as both the input and output node. Solutions to two benchmark example problems illustrate that the proposed model presents significant reductions in the pipeline operational cost.

math.DG↗
arXiv2016

On the integrability of the isotropic almost complex structures and harmonic unit vector fields

Aguilar introduced isotropic almost complex structures $J_{δ, σ}$ on the tangent bundle of a Riemannian manifold $(M, g)$. In this paper, some results will be obtained on the integrability of these structures. These structures with the Liouville 1-form define a class of Riemannian metrics $g_{δ, σ}$ on $T M$ which are a generalization of the Sasaki metric. Moreover, the notion of a harmonic unit vector field is introduced with respect to these metrics like as the Sasaki metric and the necessary and sufficient conditions for a unit vector field to be a harmonic unit vector field are obtained.

math.DG↗