6 citations · 14 across the 11 of their papers we have counts for
11 papers
Weighted Homology and Cohomology of Weighted Polyhedra
Yin Wei, Lisu Wu, Li Yu
We define the notion of weighted polyhedron which can be thought of as the geometric realization of a weighted simplicial complex introduced by Dawson. Moreover, we will define a w…
On Riemannian polyhedra with non-obtuse dihedral angles in 3-manifolds with positive scalar curvature
Li Yu
We determine the combinatorial types of all the 3-dimensional simple convex polytopes in R^3 that can be realized as mean curvature convex (or totally geodesic) Riemannian polyhedr…
Weighted homology theory of orbifolds and Weighted Polyhedra
Yin Wei, Lisu Wu, Li Yu
We introduce two new homology theories of orbifolds from some special type of triangulations adapted to an orbifold, called AW-homology and DW-homology. The main idea in the defini…
Lickorish type construction of manifolds over simple polytopes
Zhi Lü, Wei Wang, Li Yu
This paper is a survey on the Lickorish type construction of some kind of closed manifolds over simple convex polytopes. Inspired by Lickorish's theorem, we propose a method to des…
On lower bounds of the sum of multigraded Betti numbers of simplicial complexes
Li Yu
We find some general lower bounds of the sum of certain families of multigraded Betti numbers of any simplicial complex with a vertex coloring.
Fundamental groups of small covers revisited
Lisu Wu, Li Yu
We study the topology of small covers from their fundamental groups. We find a way to obtain explicit presentations of the fundamental group of a small cover. Then we use these pre…
On descriptions of products of simplices
Li Yu, Mikiya Masuda
We give several new criteria to judge whether a simple convex polytope in a Euclidean space is combinatorially equivalent to a product of simplices. These criteria are mixtures of…
Self-dual binary codes from small covers and simple polytopes
Bo Chen, Zhi Lü, Li Yu
We explore the connection between simple polytopes and self-dual binary codes via the theory of small covers. We first show that a small cover over a simple -polytope $P^n…
On Homology Roses and the D(2)-problem
Xifeng Jin, Yang Su, Li Yu
For a commutative ring with a unit, an -homology rose is a topological space whose homology groups with -coefficients agree with those of a bouquet of cirlces. In this pa…
On free -torus actions in dimension two and three
Li Yu
We confirm the Halperin-Carlsson Conjecture for free -torus actions (p is a prime) on 2-dimensional finite CW-complexes and free -torus actions on compact 3-manifolds.
Small Cover and Halperin-Carlsson Conjecture -II
Li Yu
For a small cover Q^n and any principal (Z_2)^m-bundle M^n over Q^n, it was shown in a previous work of the author that the total sum of Z_2-Betti numbers of M^n is at least 2^m. I…