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multiplyGW -- the tensor product of two Grothendieck-Witt classes

Description

Given two GrothendieckWittClass objects beta1 and beta2, this method computes the tensor product of the two classes, which is a new GrothendieckWittClass object representing the isomorphism class of the tensor product of the two symmetric bilinear forms represented by the input classes. The resulting class has a Gram matrix which is the tensor product of the Gram matrices of the two input classes.

i1 : R = QQ[x]/(x^2 + 1);
i2 : beta1 = makeGWClass matrix(R, {{1,2},{2,x}});
i3 : beta2 = makeGWClass matrix(R, {{3,4},{4,5}});
i4 : multiplyGW(beta1, beta2)

o4 = | 3 4  6  8  |
     | 4 5  8  10 |
     | 6 8  3x 4x |
     | 8 10 4x 5x |

o4 : GrothendieckWittClass

See also

Ways to use multiplyGW:

  • multiplyGW(GrothendieckWittClass,GrothendieckWittClass)

For the programmer

The object multiplyGW is a method function.


The source of this document is in A1BrouwerDegrees/Documentation/GrothendieckWittClassesDoc.m2:148:0.