arXiv subjects

Joel W. Robbin

Publications and source records attributed to Joel W. Robbin.

3 recordsLinked to original sources

arXiv2021

The moment-weight inequality and the Hilbert-Mumford criterion

This paper gives an essentially self-contained exposition (except for an appeal to the Lojasiewicz gradient inequality) of geometric invariant theory from a differential geometric viewpoint. Central ingredients are the moment-weight inequality (relating the Mumford numerical invariants to the norm of the moment map), the negative gradient flow of the moment map squared, and the Kempf-Ness function.

math.SG↗

arXiv2006

On eigenvectors of nilpotent Lie algebras of linear operators

We give a condition ensuring that the operators in a nilpotent Lie algebra of linear operators on a finite dimensional vector space have a common eigenvector.

math.RT↗

arXiv2005

A construction of the Deligne--Mumford orbifold

We define the Deligne Mumford orbifold axiomatically by a universal mapping property, show that this universal mapping property is equivalent to an infinitessimal universal mapping property, and use the latter to give an existence proof.

math.SG↗