The concept of ${mathscr{F}}_{st}$-fundamentality is introduced in uniform spaces, generated by some filter ${mathscr{F}}$. Its equivalence to the concept of ${mathscr{F}}$-convergence in uniform spaces is proved. This convergence generalizes many kinds of convergence, including the well-known statistical convergence.

a 1993 result of j. llibre, and m. misiurewicz, (theorem a [5]), states that if a continuous map f of a graph into itself has an s-horseshoe, then the topological entropy of f is greater than or equal to logs, that is h( f ) ? logs. also a 1980 result of l.s. block, j. guckenheimer, m. misiurewicz and l.s. young (lemma 1.5 [3]) states that if g is an a-graph of f then h(g) ? h( f ). in this pap...

In this paper we study the structure of locally solvable, solvable, locally nilpotent, and nilpotent maximal subgroups of skew linear groups. In [S. Akbari et al., J. Algebra 217 (1999) 422–433] it has been conjectured that if D is a division ring and M a nilpotent maximal subgroup of D∗, then D is commutative. In connection with this conjecture we show that if F [M]\F contains an algebraic ele...

13. The problem of determining all algebraic minimal surfaces was solved analytically by Weierstrass in 1866 (see his collected works, volume 3, pages 39-52). Darboux, in his Théorie générale des surfaces, part 1, No. 221, has shown that such surfaces can always be generated by the translation of an algebraic curve. This shows that the function F(s) used in the formulas of Weierstrass must be a...

Let G be a connected and reductive algebraic group over an algebraically closed field of characteristic p > 0. An interesting class of representations of G consists of those G-modules having a good filtration – i.e. a filtration whose layers are the induced highest weight modules obtained as the space of global sections of G-linearized line bundles on the flag variety of G. Let H ⊂ G be a conne...

Let F be the ag variety of a complex semi-simple group G, let H be an algebraic subgroup of G acting on F with nitely many orbits, and let V be an H-orbit closure in F. Expanding the cohomology class of V in the basis of Schubert classes deenes a union V 0 of Schubert varieties in F with positive multiplicities. If G is simply-laced, we show that these multiplicites are equal to the same power ...

There is a close relationship between Mumford’s geometric invariant theory (GIT) in (complex) algebraic geometry and the process of reduction in symplectic geometry. GIT was developed to construct quotients of algebraic varieties by reductive group actions and thus to construct and study moduli spaces [28, 29]. When a moduli space (or a compactification of a moduli space) over C can be construc...

Let G be a connected, semisimple algebraic group defined over an algebraically closed field k of characteristic p > 0. We assume that G is defined and split over the prime field k0. In general, for any positive integer r, and any affine fc-group scheme H defined over k0, the r-th infinitesimal subgroup scheme Hr of H is defined to be the (scheme-theoretic) kernel of the r-th power of the Froben...