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@kedlaya kedlaya commented Apr 27, 2024

We continue the port of hypergeometric motives from Magma by implementing the computation of hypergeometric traces and Euler factors for tame primes. This splits into two essentially separate cases: when t has nonzero p-adic valuation ("tame"), and when t-1 has nonzero p-adic valuation ("multiplicative"). In the second case, the computation uses the local functional equation as in the good reduction case.

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github-actions bot commented Apr 27, 2024

Documentation preview for this PR (built with commit 1de49be; changes) is ready! 🎉
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I am assuming the math is good (I don't really know anything about it). I just have a few minor comments about the code. Once addressed, I am willing to set a positive review.

@kedlaya kedlaya changed the title Implement hypergeometric euler factors for some tame primes Implement hypergeometric Euler factors for tame primes May 5, 2024
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kedlaya commented May 6, 2024

I think all the content is (finally) here now, but I'm not sure what's going on with the build failures in CI.

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tscrim commented May 6, 2024

Those build failures are happening across all PRs. I don't know what's going on there either.

# now p is good, or p is tame and t is a p-adic unit
elif (t-1) % p == 0:
typ = "mult"
d = (self.degree() - 1) // 2 * 2
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I still find it takes me a moment to realize that these operations should not simply cancel (and could follow my suggestion on the first round).

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Maybe it's better to be clear than concise, reworked the logic.

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For a tentative to repair the currently very broken CI , see #37926

@github-actions github-actions bot added v: large and removed v: small labels May 9, 2024
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Thank you. LGTM.

vbraun pushed a commit to vbraun/sage that referenced this pull request May 11, 2024
sagemathgh-37881: Implement hypergeometric Euler factors for tame primes
    
We continue the port of hypergeometric motives from Magma by
implementing the computation of hypergeometric traces and Euler factors
for tame primes. This splits into two essentially separate cases: when t
has nonzero p-adic valuation ("tame"), and when t-1 has nonzero p-adic
valuation ("multiplicative"). In the second case, the computation uses
the local functional equation as in the good reduction case.
    
URL: sagemath#37881
Reported by: kedlaya
Reviewer(s): kedlaya, Travis Scrimshaw
vbraun pushed a commit to vbraun/sage that referenced this pull request May 12, 2024
sagemathgh-37881: Implement hypergeometric Euler factors for tame primes
    
We continue the port of hypergeometric motives from Magma by
implementing the computation of hypergeometric traces and Euler factors
for tame primes. This splits into two essentially separate cases: when t
has nonzero p-adic valuation ("tame"), and when t-1 has nonzero p-adic
valuation ("multiplicative"). In the second case, the computation uses
the local functional equation as in the good reduction case.
    
URL: sagemath#37881
Reported by: kedlaya
Reviewer(s): kedlaya, Travis Scrimshaw
@vbraun vbraun merged commit 649c4d5 into sagemath:develop May 12, 2024
vbraun pushed a commit to vbraun/sage that referenced this pull request Jul 20, 2024
sagemathgh-38322: Implement hypergeometric Euler factors at t=1
    
Since sagemath#37881 was merged, we have the ability to compute hypergeometric
traces at the degenerate value t=1. This PR makes a few changes to
expose the corresponding functionality for Euler factors (again
following the lead of Magma).
    
URL: sagemath#38322
Reported by: kedlaya
Reviewer(s): Travis Scrimshaw
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5 participants