We prove that the Banach algebra formed by the space of compact operators on a Hilbert space endowed with the Schur product is a quotient of a uniform algebra (also known as a Q-algebra). Together with a similar result of PérezGarćıa for the trace class, this completes the answer to a long-standing question of Varopoulos.

We study the GIT-quotient of the Cartesian ppower of a projective space modulo the projective orthogonal group. A classical isomorphism of this group with the Inversive group of birational transformations of the projective space of one dimension less allows one to interpret these spaces as configuration spaces of complex or real spheres.

This paper proves that there are only finitely many subgroups H of finite index in Sp(4,Z) such that the corresponding quotient H/H of the Siegel upper half space of rank two is not of general type.

The moduli space of jets of certain G-structures (basically those which admit a canonical linear connection) is shown to be isomorphic to the quotient of a natural G-module by G.

In classical covering space theory, a covering map induces an injection of fundamental groups. This note reveals a dual property for quotient maps having connected fibers, with applications to orbit spaces of smooth vector fields and leaf spaces in general.

We identify the symmetry algebra of the Laplacian on Euclidean space as an explicit quotient of the universal enveloping algebra of the Lie algebra of conformal motions. We construct analogues of these symmetries on a general conformal manifold.

Veronese webs appear as the natural way of passing to the quotient of curves in the projective space. In this paper, we give the link between classical multidimensional webs and Veronese webs by means of interpolation.

We prove that for any isometric action of a group on unit sphere dimension larger than one, the quotient space has diameter zero or universal dimension-independent positive constant.

We show that a free period three action on the three-sphere is standard, ie, the quotient is homeomorphic to a lens space. We use a minimax argument involving sweepouts. AMS Classification numbers Primary: 57M60 Secondary: 57M50

The space of inequivalent representations of a compact surface S with χ(S) < 0 as a quotient of a convex domain in RP by a properly discontinuous group of projective transformations is a cell of dimension