5 papers · 1 filter
Nonpositively curved -manifolds with zero Euler characteristic
Chris Connell, Yuping Ruan, Shi Wang
We show that for any closed nonpositively curved Riemannian 4-manifold with vanishing Euler characteristic, the Ricci curvature must degenerate somewhere. Moreover, for each po…
The Cayley hyperbolic space and volume entropy rigidity
Yuping Ruan
Let be a Riemannian manifold with dimension greater or equal to which admits a complete, finite-volume Riemannian metric locally isometric to a rank-1 symmetric space…
Filling volume minimality and boundary rigidity of metrics close to a negatively curved symmetric metric
Yuping Ruan
This paper generalizes D. Burago and S. Ivanov's work on filling volume minimality and boundary rigidity of almost real hyperbolic metrics. We show that regions with metrics close…
An existence theorem on the isoperimetric ratio over scalar-flat conformal classes
Xuezhang Chen, Tianling Jin, Yuping Ruan
Let be a smooth compact Riemannian manifold of dimension with smooth boundary , admitting a scalar-flat conformal metric. We prove that the supremum of the…
The Han-Li conjecture in constant scalar curvature and constant boundary mean curvature problem on compact manifolds
Xuezhang Chen, Yuping Ruan, Liming Sun
The Han-Li conjecture states that: Let be an -dimensional smooth compact Riemannian manifold with boundary having positive (generalized) Yamabe constant an…