Objective: Topological phases are exotic states of quantum matter characterized by a topological invariant
of their ground state that guarantees the existence of unusual surface or edge modes with many special properties.
is an irresolute topological invariant subgroup again.
Then semi closure of any invariant subgroup of is an irresolute topological invariant subgroup again.
Then to a simply connected topological space X we associate a topological invariant [sub.
0]) is a topological space then the above construction defines a topological invariant [sub.
The only other topological invariant
used here is the concept of the number of components.
Dimension, the number of coordinates required to specify a point in a given space, is an example of a topological invariant
In mathematical terminology, Hirzebruch's problem was to determine which Chern numbers are topological invariants
of complex-algebraic varieties.
Three of the 20 papers delivered at the June 2006 conference survey algorithms for computing topological invariants
of semi-algebraic sets, problems and methods concerning k-facets and k-sets, and several points of view on pseudo-triangulations.
Some topological invariants
of isolated hypersurface singularities, EMS summer schoolEger (Hungary), 29 July-9 August (1996).
Such deformation spaces often arise as solutions to basic geometric problems, and their global properties provide powerful topological invariants
, in particular for three- and four-dimensional manifolds.
Abd El-Monsef, irresolute and topological invariants