From thapen at math.cas.cz Wed Feb 4 11:11:45 2026 From: thapen at math.cas.cz (thapen) Date: Wed, 04 Feb 2026 11:11:45 +0100 Subject: [Proof Complexity] Positions at the Academy of Sciences in Prague Message-ID: <71fbf2075bc6baa185132032247ef1c0@math.cas.cz> There is an opening at our department for a researcher in mathematical logic, computational complexity, proof complexity or set theory. This is a tenure track type position, expected to turn into a long-term contract after the initial two years. There is also an opening for a postdoc at the mathematical institute, not exclusive to our department, for two years from this summer. See https://app.math.cas.cz/public/positions The application deadline is 31 March. Please contact me at thapen at math.cas.cz if you have any questions. From jn at di.ku.dk Thu Feb 5 17:08:32 2026 From: jn at di.ku.dk (=?UTF-8?Q?Jakob_Nordstr=C3=B6m?=) Date: Thu, 5 Feb 2026 17:08:32 +0100 Subject: [Proof Complexity] MIAO seminar Fri Feb 6 at 15:15 CET with Sreejata Kishor Bhattacharya: Aaronson-Ambainis Conjecture is True for Random Restrictions Message-ID: <657590e1-0d8d-4244-8f3d-b0c97b1613d2@di.ku.dk> Dear all, With a lot of excitement, albeit with apologies for the short notice, we would like to announce a seminar tomorrow Friday February 6 at 15:15 CET (note the time!) with Sreejata Kishor Bhattacharya from the Tata Institute of Fundamental Research Mumbai, who will give a presentation titled "Aaronson-Ambainis Conjecture is True for Random Restrictions". You find the abstract at the bottom of this message. We will run this as a MIAO hybrid seminar at the IT University of Copenhagen. Local participants are warmly welcome to ITU at Rued Langgaards Vej 7, where the seminar will be held in Skybox 4A05, while other participants are equally warmly welcome to join virtually at https://lu-se.zoom.us/j/61925271827 . Please feel free to share this information with colleagues who you think might be interested. We are also hoping to record the seminar and post on the MIAO Research YouTube channel https://youtube.com/@MIAOresearch for people who would like to hear the talk but cannot attend. More information about the MIAO seminar series can be found at https://jakobnordstrom.se/miao-seminars/ . If you do not wish to receive these announcements, or receive several copies of them, please send a message to jn at di.ku.dk. Best regards, Jakob Nordstr?m ********** /Friday Feb 6 at 15:15 (note the time!) in Skybox 4A05, Rued Langgaards Vej 7, IT University of Copenhagen, and on Zoom *Aaronson-Ambainis Conjecture is True for Random Restrictions *(Sreejata Kishor Bhattacharya, Tata Institute of Fundamental Research Mumbai) / The motivating question behind this talk is the following: for what kind of problems do quantum algorithms enjoy a significant (super-polynomial) advantage over classical algorithms? We study this problem in the setting of query complexity: a model of computation where the device computing the function gets access to the input only by limited interactions with an oracle. It has been long conjectured that the probability of acceptance of a quantum query algorithm making q queries can be well-approximated in the L^2 norm by a classical query algorithm making at most poly(q) queries. Aaronson and Ambainis formulated a conjecture about bounded degree-d polynomials f:{-1,1}^n?[0,1] which implies the above conjecture. It states that any such polynomial f must have a coordinate i with influence Inf_i[f] >= poly(Var[f],1/d). The AA conjecture has recently received significant attention in the community ? there is a series of partial results and failed attempts. The main contribution of this work is showing the following: given any such f, if we consider an appropriate random restriction, with high probability the conjecture is true for the restricted function. In other words, the AA conjecture is true for random restrictions. In the end we shall sketch some potential ways of proving the full conjecture. Based on a paper in ITCS 2025 (arxiv.org/abs/2402.13952). Jakob Nordstr?m, Professor University of Copenhagen and Lund University Phone: +45 28 78 38 11 / +46 70 742 21 98 https://jakobnordstrom.se From amir.akbar at gmail.com Fri Feb 6 19:45:57 2026 From: amir.akbar at gmail.com (Amir Tabatabai) Date: Fri, 6 Feb 2026 18:45:57 +0000 Subject: [Proof Complexity] A New Preprint Message-ID: Dear all, I am happy to share our new preprint, ?Proof Complexity of Linear Logics?: https://arxiv.org/abs/2601.22393 In this work, we study the role of structural rules in the proof complexity of the sequent system LK for classical logic (equivalently, the Frege system). More precisely, we establish exponential separations between LK and its subsystems that lack either contraction or weakening. We also show that the combination of these two rules without cut is exponentially weaker than the cut rule on its own. This investigation of structural rules can be seen as a natural extension of Jan Kraj??ek?s result separating LK from its cut-free fragment. Comments, suggestions, and corrections are most welcome. Best wishes, Amir. From jn at di.ku.dk Sun Feb 8 20:30:56 2026 From: jn at di.ku.dk (=?UTF-8?Q?Jakob_Nordstr=C3=B6m?=) Date: Sun, 8 Feb 2026 20:30:56 +0100 Subject: [Proof Complexity] Danish Data Science Academy postdoc and PhD positions (deadline March 4, 2026) Message-ID: Dear colleagues, I would be most grateful for any assistance in distributing the information below about some exciting (and prestigious) postdoc and PhD openings in Denmark. Best regards, Jakob Nordstr?m ********** *Danish Data Science Academy postdoc and PhD positions (deadline March 4, 2026) * The Danish Data Science Academy invites applications for postdoc and PhD fellowships for visionary and ambitious young data scientists who want to pursue their own research ideas in collaboration with a Danish research environment. The postdoc call is at https://ddsa.dk/postdocfellowshipcall2026/ and the PhD call at https://ddsa.dk/phdfellowshipcall2026/, and the application deadline is March 4, 2026. Applications can be within any field of data science aligning with the DDSA research scope (https://ddsa.dk/ddsaresearchscope/), including, but not limited to, algorithms research within data science and AI and applications of data science or computer science to other areas in natural, technical, or life sciences. The positions will be awarded to the most promising candidates according to their scientific qualifications, motivation, and engagement, as well as the quality, originality, relevance and potential impact of the proposed project. It is a requirement that the applicant has a well-defined research project proposal as well as an agreement with a principal supervisor at a Danish university. Informal inquiries about opportunities in the Algorithms and Complexity Section at the University of Copenhagen (https://di.ku.dk/english/research/ac/) are welcome and can be directed to Jakob Nordstrom (jn at di.ku.dk) or other faculty in the section. Please contact us as soon as possible if you are interested, so that there is enough time to talk about your research ideas and provide feedback on how to turn them into a successful DDSA proposal. Jakob Nordstr?m, Professor University of Copenhagen and Lund University Phone: +46 70 742 21 98 / +45 28 78 38 11 https://jakobnordstrom.se