Here is a list of upcoming online seminars in combinatorics, automatically generated from researchseminars.org and a few other calendars available in the iCal format. Please let me know if you find any interesting iCal feed / Google Calendar of the seminars.
You can also find a list of upcoming workshops, conferences, and schools.
Timezone: Korea (KST), UTC/GMT+9.
February 2023
February 10
 12:15 am – 2:00 am

Cosmin Pohoata (IAS School of Math)
by Cosmin Pohoata (IAS School of Math) as part of CopenhagenJerusalem Combinatorics Seminar
Interactive livestream: https://ucphku.zoom.us/j/69937085835?pwd=S3J6UjQ0eFVPOU1hRUdCMHRnYXozUT09
Abstract: TBA
February 14
 4:30 pm – 5:30 pm

Raphael Steiner (ETH Zürich)
Title: Strengthening Hadwiger’s conjecture for 4 and 5chromatic graphs
by Raphael Steiner (ETH Zürich) as part of IBS/KAIST Discrete Math SeminarViewonly livestream: https://www.youtube.com/c/ibsdimag
Lecture held in Room B232, IBS.
Abstract: TBA
February 15
 4:30 pm – 5:30 pm

Robert Hickingbotham (Monash University)
Title: Treewidth, Circle Graphs and Circular Drawings
by Robert Hickingbotham (Monash University) as part of IBS Virtual Discrete Math ColloquiumAbstract: TBA
February 16
 6:00 pm – 7:00 pm

Petr A. Golovach, «Shortest cycles with monotone submodular costs»
We introduce the following submodular generalization of the Shortest Cycle problem. For a nonnegative monotone submodular cost function $f$ defined on the vertices (or, equivalently, the edges) of an undirected graph $G$, we seek for a cycle $C$ in $G$ of minimum cost $Opt=f(C)$. We construct an algorithm that, given an $n$vertex graph $G$, parameter $ε > 0$, and the function $f$ represented by an oracle, in time $n^{O(\log 1/ε)}$ finds a cycle $C$ in $G$ with $f(C)\leq (1+ε)Opt$. This is in sharp contrast with the nonapproximability of the closely related Monotone Submodular Shortest $(s,t)$Path problem, which requires exponentially many queries to the oracle for finding an $n^{2/3ε}$approximation [Goel et al., FOCS 2009]. When the function $f$ is integervalued, our algorithm yields that a cycle of cost $Opt$ can be found in time $n^{O(\log Opt)}$. In particular, for $Opt=n^{O(1)}$ this gives a quasipolynomialtime algorithm computing a cycle of minimum submodular cost.
Joint work with: Fedor V. Fomin, Tuukka Korhonen, Daniel Lokshtanov, and Giannos Stamoulis
February 17
 12:15 am – 2:00 am

Geunho Lim (University of California, Santa Barbara)
by Geunho Lim (University of California, Santa Barbara) as part of CopenhagenJerusalem Combinatorics Seminar
Interactive livestream: https://ucphku.zoom.us/j/69937085835?pwd=S3J6UjQ0eFVPOU1hRUdCMHRnYXozUT09
Abstract: TBA
February 21
 4:30 pm – 5:30 pm

Meike Hatzel (National Institute of Informatics)
Title: FixedParameter Tractability of Directed Multicut with Three Terminal Pairs Parametrised by the Size of the Cutset: TwinWidth Meets FlowAugmentation
by Meike Hatzel (National Institute of Informatics) as part of IBS/KAIST Discrete Math SeminarViewonly livestream: https://www.youtube.com/c/ibsdimag
Lecture held in Room B232, IBS.
Abstract: TBA
February 22
 5:00 pm – 6:00 pm

Daniel Altman (University of Oxford)
by Daniel Altman (University of Oxford) as part of IBS Virtual Discrete Math Colloquium
Abstract: TBA
February 24
 12:15 am – 1:15 am

Stephanie Mui (NYU Courant)
by Stephanie Mui (NYU Courant) as part of CopenhagenJerusalem Combinatorics Seminar
Interactive livestream: https://ucphku.zoom.us/j/69937085835?pwd=S3J6UjQ0eFVPOU1hRUdCMHRnYXozUT09
Abstract: TBA  1:20 am – 2:20 am

Fabio Alejandro Calderón Mateus (Universidad Nacional de Colombia)
by Fabio Alejandro Calderón Mateus (Universidad Nacional de Colombia) as part of CopenhagenJerusalem Combinatorics Seminar
Interactive livestream: https://ucphku.zoom.us/j/69937085835?pwd=S3J6UjQ0eFVPOU1hRUdCMHRnYXozUT09
Abstract: TBA
February 28
 4:30 pm – 5:30 pm

Stijn Cambie (IBS Extremal Combinatorics and Probability Group)
Title: Recent progress on the Unionclosed conjecture and related
by Stijn Cambie (IBS Extremal Combinatorics and Probability Group) as part of IBS/KAIST Discrete Math SeminarViewonly livestream: https://www.youtube.com/c/ibsdimag
Lecture held in Room B232, IBS.
Abstract: TBA
March 2023
March 2
 6:00 pm – 7:00 pm

Giannos Stamoulis, «ModelChecking for FirstOrder Logic with Disjoint Paths Predicates in Proper MinorClosed Graph Classes»
The //disjoint paths logic//, FOL+DP, is an extension of First Order Logic (FOL) with the extra atomic predicate dp$_k(x_1,y_1,\ldots,x_k,y_k),$ expressing the existence of internally vertexdisjoint paths between $x_i$ and $y_i,$ for $i\in \{1,\ldots, k\}$. This logic can express a wide variety of problems that escape the expressibility potential of FOL. We prove that for every minorclosed graph class, modelchecking for FOL+DP can be done in quadratic time. We also introduce an extension of FOL+DP, namely the //scattered disjoint paths logic//, FOL+SDP, where we further consider the atomic predicate $s$sdp$_k(x_1,y_1,\ldots,x_k,y_k),$ demanding that the disjoint paths are within distance bigger than some fixed value $s$. Using the same technique we prove that modelchecking for FOL+SDP can be done in quadratic time on classes of graphs with bounded Euler genus.
Joint work with Petr Golovach and Dimitrios M. Thilikos
March 3
 12:15 am – 2:00 am

István Tomon (Umeå University)
by István Tomon (Umeå University) as part of CopenhagenJerusalem Combinatorics Seminar
Interactive livestream: https://ucphku.zoom.us/j/69937085835?pwd=S3J6UjQ0eFVPOU1hRUdCMHRnYXozUT09
Abstract: TBA
March 7
 4:30 pm – 5:30 pm

Eunjin Oh (POSTECH)
by Eunjin Oh (POSTECH) as part of IBS/KAIST Discrete Math Seminar
Viewonly livestream: https://www.youtube.com/c/ibsdimag
Lecture held in Room B232, IBS.
Abstract: TBA
March 9
 10:00 am – 11:00 am

Marcelo Sales (Emory University)
by Marcelo Sales (Emory University) as part of IBS Virtual Discrete Math Colloquium
Abstract: TBA
March 10
 12:15 am – 2:00 am

Meghana M. Reddy (ETH Zürich)
by Meghana M. Reddy (ETH Zürich) as part of CopenhagenJerusalem Combinatorics Seminar
Interactive livestream: https://ucphku.zoom.us/j/69937085835?pwd=S3J6UjQ0eFVPOU1hRUdCMHRnYXozUT09
Abstract: TBA
March 17
 12:15 am – 2:00 am

Rosna Paul (Graz University of Technology)
by Rosna Paul (Graz University of Technology) as part of CopenhagenJerusalem Combinatorics Seminar
Interactive livestream: https://ucphku.zoom.us/j/69937085835?pwd=S3J6UjQ0eFVPOU1hRUdCMHRnYXozUT09
Abstract: TBA
March 22
 4:30 pm – 5:30 pm

Qizhong Lin (Fuzhou University)
by Qizhong Lin (Fuzhou University) as part of IBS Virtual Discrete Math Colloquium
Abstract: TBA
April 2023
April 4
 4:30 pm – 5:30 pm

István Tomon (Umeå universitet)
Title: Configurations of boxes
by István Tomon (Umeå universitet) as part of IBS/KAIST Discrete Math SeminarViewonly livestream: https://www.youtube.com/c/ibsdimag
Lecture held in Room B232, IBS.
Abstract: TBA
April 6
 10:00 am – 11:00 am

Jie Han (Beijing Institute of Technology)
by Jie Han (Beijing Institute of Technology) as part of IBS Virtual Discrete Math Colloquium
Abstract: TBA
May 2023
May 9
 4:30 pm – 5:30 pm

Maria Chudnovsky (Princeton University)
by Maria Chudnovsky (Princeton University) as part of IBS/KAIST Discrete Math Seminar
Viewonly livestream: https://www.youtube.com/c/ibsdimag
Lecture held in Room B232, IBS.
Abstract: TBA
May 16
 4:30 pm – 5:30 pm

Oliver Janzer (University of Cambridge)
by Oliver Janzer (University of Cambridge) as part of IBS/KAIST Discrete Math Seminar
Viewonly livestream: https://www.youtube.com/c/ibsdimag
Lecture held in Room B232, IBS.
Abstract: TBA