Displaying 81 – 100 of 164

Showing per page

Minimality of toric arrangements

Giacomo d'Antonio, Emanuele Delucchi (2015)

Journal of the European Mathematical Society

We prove that the complement of a toric arrangement has the homotopy type of a minimal CW-complex. As a corollary we deduce that the integer cohomology of these spaces is torsionfree. We apply discrete Morse theory to the toric Salvetti complex, providing a sequence of cellular collapses that leads to a minimal complex.

On sets of vectors of a finite vector space in which every subset of basis size is a basis

Simeon Ball (2012)

Journal of the European Mathematical Society

It is shown that the maximum size of a set S of vectors of a k -dimensional vector space over 𝔽 q , with the property that every subset of size k is a basis, is at most q + 1 , if k p , and at most q + k p , if q k p + 1 4 , where q = p k and p is prime. Moreover, for k p , the sets S of maximum size are classified, generalising Beniamino Segre’s “arc is a conic” theorem. These results have various implications. One such implication is that a k × ( p + 2 ) matrix, with k p and entries from 𝔽 p , has k columns which are linearly dependent. Another is...

Currently displaying 81 – 100 of 164