#20493: Rank of random matrices over GF(2) is bounded (again)
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       Reporter:  kedlaya                        |        Owner:
           Type:  defect                         |       Status:  new
       Priority:  major                          |    Milestone:  sage-7.2
      Component:  linear algebra                 |   Resolution:
       Keywords:  random matrices, rank,         |    Merged in:
  pseudorandom numbers                           |    Reviewers:
        Authors:                                 |  Work issues:
Report Upstream:  N/A                            |       Commit:
         Branch:                                 |     Stopgaps:  todo
   Dependencies:                                 |
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Comment (by kedlaya):

 If I understand correctly how linear pseudorandom number generators work,
 the Mersenne twister is computing iterates of a linear operator on
 `F_2^19937` which acts as a permutation of this space, and the values we
 see coming out of gmp are the result of applying some fixed linear
 projection from `F_2^19937` to `F_2^32`. Since we're simply filling those
 bits directly into the matrix, that limits the rank to 19937.

 In order to break out of this, we need to do something nonlinear with the
 gmp-provided bits...

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Ticket URL: <http://trac.sagemath.org/ticket/20493#comment:3>
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