How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
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These labels describe origin, not correctness: citations and verification chips remain separate evidence.
An extra square-root sample-size factor destroys standard-error studentization
Statement refuted
If is the estimated standard error in Studentized two-sample U-statistic and permutation distribution and , then the extra scaling still has a standard-normal limit.
Facts & Assumptions
Given: AC, the Rademacher law, , proportional sample sizes, and the sample-variance studentizer.
Two-sample U-statistic parameter: for , .
Identical distribution and IID families: the two samples are independent IID Rademacher samples.
Moments, variance, and covariance on a probability space: variance is the second centered moment.
Chebyshev's inequality on a finite probability space: sample averages of bounded IID variables converge in probability to their expectations.
Studentized two-sample U-statistic and permutation distribution: standard-error studentization sets .
Studentized permutation validity under mixed-assignment centering: when its stated hypotheses hold, both and its conditional permutation CDF converge uniformly in probability to .
AC is assumed by the asymptotic permutation limit result [F6]. The Axiom of Choice
Counterexample
Let be the Rademacher law on , take and , and let . Use the two usual sample variances in .
Given: Rademacher, , and the usual sample variances. Verify the standard-normal limits and refute the extra-scaled claim.
The two population means are zero and the two variances are one, so by [F1]. The kernel is antisymmetric, and both P/Q assignments have mean zero. For each assignment, equals on the two equal-sign pairs and on the two opposite-sign pairs, each of probability , so . The first projections are and ; each has variance .
Under AC [A1], the sample variances are measurable finite-sample statistics. Here exactly and, by [F4], the sample mean converges in probability to ; the identity then gives consistency to . The pooled mixture is the same Rademacher law, so this consistency holds in both permuted groups and the positive pooled projection variance is also . Thus [F6] applies and gives the standard-normal limits for itself and its conditional permutation distribution.
For every fixed and every , eventually , hence By the true-sampling convergence in step 1.2, the limsup of the right side is at most . Letting proves ; thus in probability.
Under AC [A1], let be the conditional permutation CDF of . For fixed , eventually , so where denotes the left limit of the conditional CDF. By [F6], the right side converges in probability to . Letting shows that the conditional probability of any fixed bounded interval tends to zero in probability. The standard-normal pivot is ; the extra factor is erroneous when the denominator is already a standard error.
Depends on
- Studentized permutation validity under mixed-assignment centering
- Studentized two-sample U-statistic and permutation distribution
- Two-sample U-statistic parameter
- Identical distribution and IID families
- Moments, variance, and covariance on a probability space
- Chebyshev's inequality on a finite probability space
- The Axiom of Choice
Used by
Nothing in the library uses this result yet.
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