<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Atsuya Hasegawa | LIP6 - Équipe QI</title><link>https://qi.lip6.fr/fr/people/atsuya-hasegawa/</link><atom:link href="https://qi.lip6.fr/fr/people/atsuya-hasegawa/index.xml" rel="self" type="application/rss+xml"/><description>Atsuya Hasegawa</description><generator>Hugo Blox Builder (https://hugoblox.com)</generator><language>fr</language><copyright>© 2022 LIP6 Quantum Information Team</copyright><lastBuildDate>Fri, 18 Jul 2025 00:00:00 +0000</lastBuildDate><image><url>https://qi.lip6.fr/media/icon_hu_bdeccd9e706ea09d.png</url><title>Atsuya Hasegawa</title><link>https://qi.lip6.fr/fr/people/atsuya-hasegawa/</link></image><item><title>Atsuya Hasegawa - Maximum Separation of Quantum Communication Complexity With and Without Shared Entanglement</title><link>https://qi.lip6.fr/fr/seminars/2025-07-18-atsuya-hasegawa/</link><pubDate>Fri, 18 Jul 2025 00:00:00 +0000</pubDate><guid>https://qi.lip6.fr/fr/seminars/2025-07-18-atsuya-hasegawa/</guid><description>&lt;h2 id="maximum-separation-of-quantum-communication-complexity-with-and-without-shared-entanglement"&gt;Maximum Separation of Quantum Communication Complexity With and Without Shared Entanglement&lt;/h2&gt;
&lt;p&gt;Ce séminaire, donné par Atsuya Hasegawa, aura lieu le 18 July 2025, à 14:0.
Il aura lieu en salle Not specified.&lt;/p&gt;
&lt;p&gt;Vous trouverez un plan du campus &lt;a href="https://sciences.sorbonne-universite.fr/vie-de-campus-sciences/accueil-vie-pratique/plan-du-campus" target="_blank" rel="noopener"&gt;ici&lt;/a&gt;.&lt;/p&gt;
&lt;h2 id="résumé"&gt;Résumé&lt;/h2&gt;
&lt;p&gt;We present relation problems whose input size is n such that they can be solved with no communication for entanglement-assisted quantum communication models, but require Ω(n) qubit communication for 2-way quantum communication models without prior shared entanglement. This is the maximum separation of quantum communication complexity with and without shared entanglement. To our knowledge, our result even shows the first lower bound on quantum communication complexity without shared entanglement when the upper bound of entanglement-assisted quantum communication models is zero. The problem we consider is parallel repetition of any non-local game which has a perfect quantum strategy and no perfect classical strategy, and for which a parallel repetition theorem holds with exponential decay. Based on joint work with Francois Le Gall and Augusto Modanese (arXiv:2505.16457).&lt;/p&gt;</description></item></channel></rss>