Israel Journal of Mathematics

, Volume 117, Issue 1, pp 335–352 | Cite as

The quantum euler class and the quantum cohomology of the Grassmannians

  • Lowell Abrams


The Poincaré duality of classical cohomology and the extension of this duality to quantum cohomology endows these rings with the structure of a Frobenius algebra. Any such algebra possesses a canonical “characteristic element;” in the classical case this is the Euler class, and in the quantum case this is a deformation of the classical Euler class which we call the “quantum Euler class.” We prove that the characteristic element of a Frobenius algebraA is a unit if and only ifA is semisimple, and then apply this result to the cases of the quantum cohomology of the finite complex Grassmannians, and to the quantum cohomology of hypersurfaces. In addition we show that, in the case of the Grassmannians, the [quantum] Euler class equals, as [quantum] cohomology element and up to sign, the determinant of the Hessian of the [quantum] Landau-Ginzbug potential.


Complete Intersection Classical Cohomology Characteristic Element Dual Basis Euler Class 
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Copyright information

© Hebrew University 2000

Authors and Affiliations

  1. 1.Department of MathematicsRutgers UniversityNew BrunswickUSA

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