fplll / fpylll

A Python interface for https://github.com/fplll/fplll
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The chiral reservation of the lattice basis before and after lattice reduction. #237

Closed hongyi-zhao closed 1 year ago

hongyi-zhao commented 1 year ago

Suppose A is the original lattice, and B is the result obtained by lattice reduction. If I want to retain the chirality of the bases before and after the lattice reduction, aka, Det[A] == Det[B]. I'm not sure whether this is possible.

See here for the related discussion.

Regards, Zhao

malb commented 1 year ago

Lattice reduction is multiplication by an unimodular transformation matrix and thus leaves the determinant unchanged.

hongyi-zhao commented 1 year ago

By convention, an unimodular matrix M is a square integer matrix having determinant +1 or -1, as described below:

image

This does not seem to be consistent with your above statement.

malb commented 1 year ago

Flip the sign of a row then.