English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Let 2; be a complete d-dimensional fan, i.e. a complex of closed convex polyhedral cones in R d with apex 0, generated by primitive lattice points Vl . . . . . v, ~ Z d, such that ~ ) ~ a = R d. Denote the q-skeleton of 2; by S ~ = { a ~ X l d i m a = q}. The polyhedral cells obtained by intersecting each cone a ~ X, a 4: {0}, with the unit sphere S d l c R d form a spherical complex C. Let S(C) be the barycentric subdivision of C and for a e Z, a 4: {0}, let # be the union of all simplices of S(C) whose vertices are barycenters of cells of C which contain a n S d-1 For a = {0} we set # = B d, the unit ball of R d, and call 2~ = { # l a s S } the dual complex of 2;. Let T d denote the d-dimensional torus Rd/Z d. Each k-dimensional cone a EZ spans a k-dimensional subspace of R d which, since it has a rational basis, maps under the projection R a ~ T d to a k-dimensional subtorus T,~ ~ T d. The toric variety X z is defined to be the. quotient Bax Td/ where (x, t ) ~ (x', t ') if and only if x = x ' e i n t # and t and t' belong to the same orbit of the natural action of T~ on T d. Note that the torus T d over a point x e int # is collapsed by the relation ~ to the quotient 7~, = Td/T,, which is a torus of dimension d dim a = dim ~. We denote by p the obvious projection of X~ onto B d and will identify p 1 (int ~) with int ~ x 7~. The proofs of the following properties can be found e.g. in I-2].

Which 4-manifolds are toric varieties?