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A Counterexample to Talagrand's Operator Cotype Problem
Abstract
Talagrand asked whether the Rademacher cotype of an operator is universally controlled by the maximum of its Gaussian cotype and its (q,1)-summing norm. We give a negative answer already for q=2. The counterexample was discovered by ChatGPT (GPT-5.6).
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BibTeX
@misc{wu2026counterexample,
title = {{A Counterexample to Talagrand's Operator Cotype Problem}},
author = {Xinglong Wu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.19731},
eprint = {2609.19731},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.19731},
}
RIS
TY - UNPB
TI - A Counterexample to Talagrand's Operator Cotype Problem
AU - Xinglong Wu
PY - 2026
DA - 2026/09/17
PB - arXiv
DO - 10.48550/arxiv.2609.19731
UR - https://arxiv.org/abs/2609.19731
AB - Talagrand asked whether the Rademacher cotype of an operator is universally controlled by the maximum of its Gaussian cotype and its (q,1)-summing norm. We give a negative answer already for q=2. The counterexample was discovered by ChatGPT (GPT-5.6).
ER -