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A proof of the stratified Morse inequalities for singular complex algebraic curves using the Witten deformation

Ursula Ludwig (2011)

Annales de l’institut Fourier

The Witten deformation is an analytic method proposed by Witten which, given a Morse function f : M R on a smooth compact manifold M , allows to prove the Morse inequalities. The aim of this article is to generalise the Witten deformation to stratified Morse functions (in the sense of stratified Morse theory as developed by Goresky and MacPherson) on a singular complex algebraic curve. In a previous article the author developed the Witten deformation for the model of an algebraic curve with cone-like singularities...

A remark on the Picard group of spin moduli space

Maurizio Cornalba (1991)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

We describe a number of classes in the Picard group of spin moduli space and determine the relations they satisfy; as an application we show that the Picard group in question contains 4-torsion elements.

A support theorem for Hilbert schemes of planar curves

Luca Migliorini, Vivek Shende (2013)

Journal of the European Mathematical Society

Consider a family of integral complex locally planar curves whose relative Hilbert scheme of points is smooth. The decomposition theorem of Beilinson, Bernstein, and Deligne asserts that the pushforward of the constant sheaf on the relative Hilbert scheme splits as a direct sum of shifted semisimple perverse sheaves. We will show that no summand is supported in positive codimension. It follows that the perverse filtration on the cohomology of the compactified Jacobian of an integral plane curve...

A Torelli theorem for moduli spaces of principal bundles over a curve

Indranil Biswas, Norbert Hoffmann (2012)

Annales de l’institut Fourier

Let X and X be compact Riemann surfaces of genus 3 , and let G and G be nonabelian reductive complex groups. If one component G d ( X ) of the coarse moduli space for semistable principal G –bundles over X is isomorphic to another component G d ( X ) , then X is isomorphic to X .

Abelova cena v roce 2018 udělena za Langlandsův program

Vítězslav Kala (2018)

Pokroky matematiky, fyziky a astronomie

V článku motivujeme a vysvětlíme základy Langlandsova programu, sítě domněnek propojujících řadu různých oblastí matematiky. Během toho se také setkáme s Riemannovou hypotézou a domněnkou Birche a Swinnerton-Dyera, dvěma ze sedmi problémů tisíciletí vyhlášených Clayovým matematickým institutem.

About G -bundles over elliptic curves

Yves Laszlo (1998)

Annales de l'institut Fourier

Let G be a complex algebraic group, simple and simply connected, T a maximal torus and W the Weyl group. One shows that the coarse moduli space M G ( X ) parametrizing S -equivalence classes of semistable G -bundles over an elliptic curve X is isomorphic to [ Γ ( T ) Z X ] / W . By a result of Looijenga, this shows that M G ( X ) is a weighted projective space.

Algebraic and symplectic Gromov-Witten invariants coincide

Bernd Siebert (1999)

Annales de l'institut Fourier

For a complex projective manifold Gromov-Witten invariants can be constructed either algebraically or symplectically. Using the versions of Gromov-Witten theory by Behrend and Fantechi on the algebraic side and by the author on the symplectic side, we prove that both points of view are equivalent

Algebraic loop groups and moduli spaces of bundles

Gerd Faltings (2003)

Journal of the European Mathematical Society

We study algebraic loop groups and affine Grassmannians in positive characteristic. The main results are normality of Schubert-varieties, the construction of line-bundles on the affine Grassmannian, and the proof that they induce line-bundles on the moduli-stack of torsors.

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