The action of a noncompact semisimple Lie group G on a finite dimensional real vector space V is said to be stable if there exists a nonempty Zariski open subset O of V such that the orbit G(v) is closed in V for all v ∈ O. We study a Hilbert-Mumford numerical function M : V → R defined by A. Marian that extends the corresponding function in the complex setting defined by D. Mumford and studied...

We ask whether the notion of a homotopy class of a path on a complex algebraic variety admits a purely algebraic characterisation, and reformulate this question as a question of categoricity of the universal covering space of a complex algebraic variety in a natural countable in nitary language. We provide partial positive results towards the question. Assuming a conjecture of Shafarevich and s...

Let V be a valuation domain of rank one with quotient field K. We study the set extensions to rational functions K(X) induced by pseudo-convergent sequences K from topological point view, endowing this either Zariski or constructible topology. In particular, we consider two subspaces prescribed breadth pseudo-limit. give some necessary conditions for space metrizable (under topology) in terms v...

We use functoriality of tropicalization and the geometry of projections of subvarieties of tori to show that the fibers of the tropicalization map are dense in the Zariski topology. For subvarieties of tori over fields of generalized power series, points in each tropical fiber are obtained “constructively” using Kedlaya’s transfinite version of Newton’s method.

There is a close relationship between the embedded topology of complex plane curves and (group-theoretic) arithmetic elliptic curves. In recent paper, we studied some arrangements that include special smooth component, via torsion properties induced by divisors in curve associated to remaining components, which an property. When this has maximal flexes, there natural isomorphism its Jacobian va...

1 Affine schemes 4 1.1 Motivation and review of varieties . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2 First attempt at defining an affine scheme . . . . . . . . . . . . . . . . . . . 4 1.3 Affine schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.4 The Zariski topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.5 The ringed space s...

A meadow is a zero totalised field (0 = 0), and a cancellation meadow is a meadow without proper zero divisors. In this paper we consider differential meadows, i.e., meadows equipped with differentiation operators. We give an equational axiomatization of these operators and thus obtain a finite basis for differential cancellation meadows. Using the Zariski topology we prove the existence of a d...

We show that if a group automorphism of Cremona arbitrary rank is also homeomorphism with respect to either the Zariski or Euclidean topology, then it inner up field base-field. Moreover, we similar result holds consider groups polynomial automorphisms affine spaces instead groups.

The nature of finitely generated infinite index subgroups of SL(3,Z) remains extremely mysterious. It follows from the famous theorem of Tits [12] that free groups abound and, moreover, Zariski dense free groups abound. Less trivially, classical arithmetic considerations (see for example §6.1 of [9]) can be used to construct surface subgroups of SL(3,Z) of every genus ≥ 2. However these are con...