Weyl closure of hypergeometric systems.
Weylgruppe und Momentabbildung.
When does a Bounded Domain Cover a Projective Manifold? (Survey)
* The research has been partially supported by Bulgarian Funding Organizations, sponsoring the Algebra Section of the Mathematics Institute, Bulgarian Academy of Sciences, a Contract between the Humboldt Univestit¨at and the University of Sofia, and Grant MM 412 / 94 from the Bulgarian Board of Education and TechnologyThe present survey introduces in some classical properties of the universal coverings of the projective algebraic manifolds. All the results are non-original. A forthcoming note is...
When is a complex elliptic curve the product of two real algebraic curves?
When is a group homomorphism a covering homomorphism?
When is a Ring of Torus Invariants a Polynomial Ring?
When is an Abelian Surface Isomorphic or Isogeneous to a Product of Elliptic Curves?
When K + (n-4) L fails to be Nef.
When Ramification points meet.
Which 3-manifold groups are Kähler groups?
The question in the title, first raised by Goldman and Donaldson, was partially answered by Reznikov. We give a complete answer, as follows: if can be realized as both the fundamental group of a closed 3-manifold and of a compact Kähler manifold, then must be finite—and thus belongs to the well-known list of finite subgroups of , acting freely on .
Which 4-manifolds are toric varieties?
Which Abelian Surfaces are Products of Elliptic Curves ?
Which weakly ramified group actions admit a universal formal deformation?
Consider a representation of a finite group as automorphisms of a power series ring over a perfect field of positive characteristic. Let be the associated formal mixed-characteristic deformation functor. Assume that the action of is weakly ramified, i.e., the second ramification group is trivial. Example: for a group action on an ordinary curve, the action of a ramification group on the completed local ring of any point is weakly ramified.We prove that the only such that are not pro-representable...
Whitney stratification of sets definable in the structure
The aim of this paper is to prove that every subset of definable from addition, multiplication and exponentiation admits a stratification satisfying Whitney’s conditions a) and b).
Whitney triangulations of semialgebraic sets
A compact semialgebraic set admits a semialgebraic triangulation such that the family of open simplexes forms a Whitney stratification and is compatible with a finite number of given semialgebraic subsets.
Whittaker and Bessel functors for
The theory of Whittaker functors for is an essential technical tools in Gaitsgory’s proof of the Vanishing Conjecture appearing in the geometric Langlands correspondence. We define Whittaker functors for and study their properties. These functors correspond to the maximal parabolic subgroup of , whose unipotent radical is not commutative.We also study similar functors corresponding to the Siegel parabolic subgroup of , they are related with Bessel models for and Waldspurger models for .We...
Whittaker functions, prehomogeneous vector spaces and standard representations of p-adic groups.
Wild Multidegrees of the Form (d,d₂,d₃) for Fixed d ≥ 3
Let d be any integer greater than or equal to 3. We show that the intersection of the set mdeg(Aut(ℂ³))∖ mdeg(Tame(ℂ³)) with {(d₁,d₂,d₃) ∈ (ℕ ₊)³: d = d₁ ≤ d₂≤ d₃} has infinitely many elements, where mdeg h = (deg h₁,...,deg hₙ) denotes the multidegree of a polynomial mapping h = (h₁,...,hₙ): ℂⁿ → ℂⁿ. In other words, we show that there are infinitely many wild multidegrees of the form (d,d₂,d₃), with fixed d ≥ 3 and d ≤ d₂ ≤ d₃, where a sequence (d₁,...,dₙ)∈ ℕ ⁿ is a wild multidegree if there is...
Wild ramification of moduli spaces for curves or for abelian varieties
Wiles dokázal Taniyamovu hypotézu; důsledkem je Fermatova věta