Singular Bilinear Integrals in Quantum Physics

Singular Bilinear Integrals in Quantum Physics

Bilinear integrals of operator-valued functions with respect to spectral measures and integrals of scalar functions with respect to the product of two spectral measures arise in many problems in scattering theory and spectral analysis. Unfortunately, the theory of bilinear integration with respect to a vector measure originating from the work of Bartle cannot be applied due to the singular vari...

Weighted estimates for rough bilinear singular integrals via sparse domination

We prove weighted estimates for rough bilinear singular integral operators with kernel K(y1, y2) = Ω((y1, y2)/|(y1, y2)|) |(y1, y2)| , where yi ∈ R and Ω ∈ L∞(S2d−1) with ∫ S2d−1 Ωdσ = 0. The argument is by sparse domination of rough bilinear operators, via an abstract theorem that is a multilinear generalization of recent work by CondeAlonso, Culiuc, Di Plinio and Ou, 2016. We also use recent ...

Physics of Singular Points in Quantum Mechanics

Defects or junctions in materials serve as a source of interactions for particles, and in idealized limits they may be treated as singular points yielding contact interactions. In quantum mechanics, these singularities accommodate an unexpectedly rich structure and thereby provide a variety of physical phenomena, especially if their properties are controlled properly. Based on our recent studie...

Singular Integrals

In this paper I will a t tempt to describe the subject as it has developed in the last fifteen years, outlining the methods by which its problems have been approached and discussing its connections with other branches of Analysis. I t will perhaps be best to start by considering certain classical situations which lead naturally to singular integrals and which contain the seeds of some of the me...

Multi-parameter singular integrals