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HodgeIntegrals :: psi

psi -- cotangent line class



This is an element in the ring created by hodgeRing. It is the $i$-th cotangent line class. Definitions and properties can be found in [AC].

Here is a simple example which calculates $\int_{{\bar M}_{1,1}} \psi_1$.

i1 : R = hodgeRing (1, 1);
i2 : psi_1

o2 = psi

o2 : R
i3 : integral(1, 1, psi_1)
warning: clearing value of symbol tempCh to allow access to subscripted variables based on it
       : debug with expression   debug 1257   or with command line option   --debug 1257

o3 = --

o3 : R


[AC] Arbarello, E. and Cornalba, M. Combinatorial and algebro-geometric cohomology classes on the moduli spaces of curves. J. Algebraic Geom. 5. (1996), no. 4, 705--749.

See also

For the programmer

The object psi is an indexed variable table.