The next meeting of the seminar of department MATHEMATICAL FOUNDATIONS OF INFORMATICS will be held on July 24, 2025, at 2:00 p.m. in room 403. Prof. Mark Iwen will deliver a talk on: Sparse Spectral Methods for Solving High-Dimensional and Multiscale Elliptic PDEs Prof. Iwen is part of the Department of Computational Mathematics of Michigan State University. His research interests include mathematical data science, signal processing and others. The talk will include some unexpected connections to certain error-correcting codes. Abstract. In his monograph "Chebyshev and Fourier Spectral Methods", John Boyd claimed that, regarding Fourier spectral methods for solving differential equations, "[t]he virtues of the Fast Fourier Transform will continue to improve as the relentless march to larger and larger [bandwidths] continues" [1, pg. 194]. This [...]

The seminar on MATHEMATICAL FOUNDATIONS OF COMPUTER SCIENCE organized by the Department of Mathematical Foundations of Informatics at IMI - BAS and the Faculty of Mathematics and Informatics of Veliko Tarnovo University (VTU), would like to invite you to the next meeting on July 3, 2025 at 2:30 p.m. in room 508, building 4 of VTU. Svetoslava Minkova Master Degree Program in Mathematical Structures in Information Security Faculty of Mathematics and Informatics, Veliko Tarnovo University will deliver a talk on: Weisfeiler-Leman algorithm and graph isomorphism invariants  

The seminar on MATHEMATICAL FOUNDATIONS OF COMPUTER SCIENCE organized by the Department of Mathematical Foundations of Informatics at IMI - BAS and the Faculty of Mathematics and Informatics of Veliko Tarnovo University (VTU), would like to invite you to the next meeting on January 8, 2025 at 5:00 p.m. in room 401 of building 4 of VTU. Prof. Ferruh Özbudak Sabancı University Faculty of Engineering and Natural Sciences, İstanbul - Turkiye will deliver a talk on: Generalizing the Bierbrauer—Friedman bound to mixed-level orthogonal arrays (joint work with Denis Krotov and Vladimir Potapov) Abstract: We characterize mixed-level orthogonal arrays it terms of algebraic designs in a special multigraph. We prove a mixed-level analog of the Bierbrauer--Friedman (BF) bound for pure-level orthogonal arrays and show that [...]

The next meeting of the Mathematical Foundations of Informatics seminar will be held on October 2, 2024, at 2:00 p.m. in Room 478 of the Institute of Mathematics and Informatics. A talk on: Lipschitz Permutations on Certain Graphs will be delivered by Dragomir Grozev. Abstract

The next meeting of the Mathematical Foundations of Informatics seminar will be held on February 8, 2024, at 3:00 p.m. in Room 256 of the Institute of Mathematics and Informatics. A talk on: Extremal problems in Euclidean combinatorial geometry will be delivered by Assoc. Prof. Danila Cherkashin. Abstract.  I will talk about several problems in the intersection of extremal combinatorics and Euclidean geometry. Recent results on the Steiner tree problem, Gilbert-Steiner problem, and Nelson-Hadwiger problem will be presented. The seminar will be streamed at  https://meet.jit.si/IMI-MOI-14400

The next meeting of the Mathematical Foundations of Informatics seminar will be held on November 10, 2023, at 2 p.m. in Room 478 of the Institute of Mathematics and Informatics. A talk on: On induced C_4 -free graphs with high average degree will be delivered by Antonio Girao. Abstract. A long-standing conjecture of Thomassen from the 80's states that every graph with sufficiently high average degree contains a subgraph with high girth and still preserving large enough average degree. This conjecture has only been resolved in the early 2000's by Kühn and Osthus in the first non-trivial case i.e. they showed that for every k , there is f(k) such the every graph with average degree at least f(k) contains a subgraph which [...]

The next meeting of the Mathematical Foundations of Informatics seminar will be held on October 31, 2023, at 4 p.m. in Room 578 of the Institute of Mathematics and Informatics. A talk on: On binary codes with distances d and d+2 will be delivered by Dr. Konstantin Vorobev, IMI - BAS. Abstract. In this work, we consider the problem of determining the exact value of A_2(n, {d, d+2}) defined as the maximal cardinality of a binary code of length n with two possible distances d and d+2 . We prove that for fixed even d and n big enough, an optimal code must be a constant-weight code of weight d/2+1 with possibly no more than one additional codeword of a [...]

The next meeting of the Mathematical Foundations of Informatics seminar will be held on August 22, 2023, at 4 p.m. in Room 503 of the Institute of Mathematics and Informatics. A talk on: Data Attribution: Scaling up and Applications to Defending Against Backdoor Attacks will be delivered by Kristian Georgiev, PhD student at MIT under the guidance of Aleksander Mądry. Abstract. The goal of data attribution is to trace model predictions back to training data. Despite a long line of work towards this goal, existing approaches to data attribution tend to force users to choose between computational tractability and efficacy. That is, computationally tractable methods can struggle with accurately attributing model predictions in non-convex settings (e.g., in the context of deep neural networks), while [...]

The next meeting of the Mathematical Foundations of Informatics seminar will be held on June 27th, 2023, at 2 p.m. in Room 278 of the Institute of Mathematics and Informatics. A talk on: The Erdős Box Problem and the Combinatorial Nullstellensatz will be delivered by Dr. Alexey Gordeev, guest researcher. Abstract. The Erdős box problem can be formulated as follows: how many points of {1,2,…,n}^m can we take so that for every m-dimensional box (hyperrectangle with sides parallel to coordinate axes) at least one of its vertices is not taken? When m is fixed and n increases, an order of growth of this number is known only in the case m=2. I will talk about Alon’s Combinatorial Nullstellensatz and its connection with the Erdős [...]

The next meeting of the Mathematical Foundations of Informatics seminar will be held on May 10, 2023, at 3 p.m. (UTC+2) in Room 503 of the Institute of Mathematics and Informatics. A talk on: Ternary self-dual codes, Hadamard matrices and related designs will be delivered by Prof. Vladimir D. Tonchev, Michigan Technological University, Houghton, USA. Abstract.