Real algebraic principal abelian fibrations

1995
If M is a closed smooth manifold, it is well known that M is diffeomorphic to a nonsingular real algebraic set. Let G be a finite group and let X→πY be a principal G-fibration where X and Y are closed smooth manifolds. By the first sentence, we can assume Y is a nonsingular real algebraic set. Question: Is X→πY differentiably equivalent to an algebraic principal G-fibration X~→π~Y (X~, π~ and the action of G on X~ all algebraic)? The author defines an "algebraic cohomology group'' H1A(Y,G) in the case G=(Z/2)k×H, where H is an abelian group of odd order. It is a subgroup of H1(Y,G) and generalizes the usual notion of algebraic cohomology when G=Z/2. The above question is then answered as follows: The existence of X~→π~Y is equivalent to the existence of a regular (= algebraic) classifying map ϕ:Y→K(G,1). Here K(G,1) is an Eilenberg-Mac Lane space which can be realized as the limit of algebraic sets (this uses the special assumption on the type of G) so that algebraicity of the classifying map makes sense. A typical application of the above is the construction of compact nonsingular algebraic sets which admit no nontrivial algebraic G-fibrations.
Contemporary Math

Suggestions

Relative topology of real algebraic varieties in their complexifications
Ozan, Yıldıray (Mathematical Sciences Publishers, 2004-12-01)
We investigate, for a given smooth closed manifold M, the existence of an algebraic model X for M (i.e., a nonsingular real algebraic variety diffeomorphic to M) such that some nonsingular projective complexification i:X-->X-C of X admits a retraction r:X-C-->X. If such an X exists, we show that M must be formal in the sense of Sullivan's minimal models, and that all rational Massey products on M are trivial.
Invariant densities and mean ergodicity of Markov operators
Emelyanov, Eduard (2003-01-01)
We prove that a, Markov operator T on L-1 has an invariant density if and only if there exists a density f that satisfies lim sup(n-->infinity) parallel toT(n) f-fparallel to infinity) parallel toP(n)f - wparallel to < 2 for every density f. Corresponding results hold for strongly continuous semigroups.
Hilbert functions of Gorenstein monomial curves
Arslan, Feza; Mete, Pinar (American Mathematical Society (AMS), 2007-01-01)
It is a conjecture due to M. E. Rossi that the Hilbert function of a one-dimensional Gorenstein local ring is non-decreasing. In this article, we show that the Hilbert function is non-decreasing for local Gorenstein rings with embedding dimension four associated to monomial curves, under some arithmetic assumptions on the generators of their de. ning ideals in the non-complete intersection case. In order to obtain this result, we determine the generators of their tangent cones explicitly by using standard b...
Quasi-constricted linear operators on Banach spaces
Wolff, MPH; Emel'yanov, Eduard Yu. (2001-01-01)
Let X be a Banach space over C. The bounded linear operator T on X is called quasi-constricted if the subspace X-0 := {x epsilon X : lim(n --> infinity) parallel toT(n)x parallel to = 0} is closed and has finite codimension. We show that a power bounded linear operator T epsilon L(X) is quasi-constricted iff it has an attractor A with Hausdorff measure of noncompactness chi parallel to (.)parallel to (1) (A) )over bar>T is mean ergodic for all lambda in the peripheral spectrum sigma (pi)(T) of T is constric...
Effective Mass Quantum Systems with Displacement Operator: Inverse Square Plus Coulomb-Like Potential
Arda, Altug; Sever, Ramazan (2015-10-01)
The Schrodinger-like equation written in terms of the displacement operator is solved analytically for a inverse square plus Coulomb-like potential. Starting from the new Hamiltonian, the effects of the spatially dependent mass on the bound states and normalized wave functions of the "usual" inverse square plus Coulomb interaction are discussed.
Citation Formats
Y. Ozan, “Real algebraic principal abelian fibrations,” Contemporary Math, 1995, Accessed: 00, 2021. [Online]. Available: https://mathscinet.ams.org/mathscinet-getitem?mr=1318735.