we establish some relative volume comparison theorems for extremal volume forms of‎ ‎finsler manifolds under suitable curvature bounds‎. ‎as their applications‎, ‎we obtain some results on curvature and topology of finsler manifolds‎. ‎our results remove the usual assumption on s-curvature that is needed in the literature‎.

There are various notions of “boundaries at infinity” of metric spaces in the literature. Perhaps the best known is the ideal boundary ∂IX defined using geodesic rays, and particularly studied for the classes of CAT(0) and proper geodesic Gromov hyperbolic spaces. Closely related to this is the concept of a Gromov boundary ∂GX defined using Gromov sequences (or “sequences converging to infinity...

The crepant resolution conjecture states that the Gromov–Witten invariants of an orbifold X should be determined in a precise way by the Gromov–Witten invariants of a crepant resolution of its coarse moduli space. We compute the Gromov–Witten invariants of the stack symmetric square of P 2 and compare them with the Gromov– Witten invariants of its crepant resolution, Hilb 2 P 2 (which were comp...

1. Properties of J-holomorphic curves 1 1.1. Basic definitions 1 1.2. Unique continuation and critical points 5 1.3. Simple curves 8 1.4. Adjunction inequality 9 2. Gromov compactness 12 2.1. Gromov compactness theorem 12 2.2. Energy estimate and bubbling 15 2.3. The isoperimetric inequality 19 2.4. Bubbles connect 22 3. Moduli spaces of J-holomorphic curves 25 3.1. The Fredholm setup 25 3.2. T...

In this paper we prove that Urysohn univeral space is hyperconvex. We also examine the Gromov hyperbolicity and hyperconvexity of metric spaces. Using fourpoint property, we give a proof of the fact that hyperconvex hull of a δ-Gromov hyperbolic space is also δ-Gromov hyperbolic.

The unit ball B is shown to be Gromov hyperbolic with respect to the Ferrand metric λBn and the modulus metric μBn , and dimension dependent upper bounds for the Gromov delta are obtained. In the two-dimensional case Gromov hyperbolicity is proved for all simply connected domains G. For λG also the case G = R n \ {0} is studied.

We make a precise mathematical statement of the conjecture that Gromov-Witten theory on an orbifold should be equivalent to Gromov-Witten theory on a crepant resolution (should one exist.) We prove the conjecture for the equivariant Gromov-Witten theories of Symn C and Hilbn C.

Given a holomorphic vector bundle E over a compact Kähler manifold X, one defines twisted Gromov-Witten invariants of X to be intersection numbers in moduli spaces of stable maps f : Σ → X with the cap product of the virtual fundamental class and a chosen multiplicative invertible characteristic class of the virtual vector bundle H0(Σ, f∗E) H1(Σ, f∗E). Using the formalism of quantized quadratic...

A quantized metric space is a matrix order unit space equipped with an operator space version of Rieffel’s Lip-norm. We develop for quantized metric spaces an operator space version of quantum Gromov-Hausdorff distance. We show that two quantized metric spaces are completely isometric if and only if their quantized Gromov-Hausdorff distance is zero. We establish a completeness theorem. As appli...