21 citations · 55 across the 14 of their papers we have counts for
6 papers · 1 filter
Moments of random quantum marginals via Weingarten calculus
Sho Matsumoto, Colin McSwiggen
The randomized quantum marginal problem asks about the joint distribution of the partial traces ("marginals") of a uniform random Hermitian operator with fixed spectrum acting on a…
Projections of Orbital Measures and Quantum Marginal Problems
Benoît Collins, Colin McSwiggen
This paper studies projections of uniform random elements of (co)adjoint orbits of compact Lie groups. Such projections generalize several widely studied ensembles in random matrix…
Revisiting Horn's Problem
Robert Coquereaux, Colin McSwiggen, Jean-Bernard Zuber
We review recent progress on Horn's problem, which asks for a description of the possible eigenspectra of the sum of two matrices with known eigenvalues. After revisiting the class…
On Horn's Problem and its Volume Function
Robert Coquereaux, Colin McSwiggen, Jean-Bernard Zuber
We consider an extended version of Horn's problem: given two orbits and of a linear representation of a compact Lie group, let ,…
The Harish-Chandra integral: An introduction with examples
Colin McSwiggen
This expository paper introduces the theory of Harish-Chandra integrals, a family of special functions that express the integral of an exponential function over the adjoint orbits…
A new proof of Harish-Chandra's integral formula
Colin McSwiggen
We present a new proof of Harish-Chandra's formula $$Π(h_1) Π(h_2) \int_G e^{\langle \mathrm{Ad}_g h_1, h_2 \rangle} dg = \frac{ [ \! [ Π, Π] \!] }{|W|} \sum_{w \in W} ε(w) e^{\lan…