Previous Page 5

Displaying 81 – 88 of 88

Showing per page

Explicit Selmer groups for cyclic covers of ℙ¹

Michael Stoll, Ronald van Luijk (2013)

Acta Arithmetica

For any abelian variety J over a global field k and an isogeny ϕ: J → J, the Selmer group S e l ϕ ( J , k ) is a subgroup of the Galois cohomology group H ¹ ( G a l ( k s / k ) , J [ ϕ ] ) , defined in terms of local data. When J is the Jacobian of a cyclic cover of ℙ¹ of prime degree p, the Selmer group has a quotient by a subgroup of order at most p that is isomorphic to the ‘fake Selmer group’, whose definition is more amenable to explicit computations. In this paper we define in the same setting the ‘explicit Selmer group’, which is isomorphic...

Exposé on a conjecture of Tougeron

Joseph Becker (1977)

Annales de l'institut Fourier

An algebra homomorphism of the locatized affine rings of an algebraic variety is continuous in the Krull topology of the respective local rings. It is not necessarily open or closed in the Krull topology. However, we show that the induced map on the associated analytic local rings is also open and closed in the Krull topology. To do this we prove a conjecture of Tougeron which states that if η is an analytic curve on an analytic variety V and f is a formal power series which is convergent when restricted...

Extremal properties for concealed-canonical algebras

Michael Barot, Dirk Kussin, Helmut Lenzing (2013)

Colloquium Mathematicae

Canonical algebras, introduced by C. M. Ringel in 1984, play an important role in the representation theory of finite-dimensional algebras. They also feature in many other mathematical areas like function theory, 3-manifolds, singularity theory, commutative algebra, algebraic geometry and mathematical physics. We show that canonical algebras are characterized by a number of interesting extremal properties (among concealed-canonical algebras, that is, the endomorphism rings of tilting bundles on...

Currently displaying 81 – 88 of 88

Previous Page 5