Sunday 19 May 2024 |
Events for day: Wednesday 06 April 2022 |
14:00 - 15:00 Combinatorics and Computing Weekly Seminar Graph Coloring and Homomorphisms to Signed Cycles School MATHEMATICS A graph $G$ is $(2k+1)$-colorable if and only if the graph $T_{2k-1}(G)$, obtained from $G$ by replacing each edge with a path of length $2k-1$, admits a homomorphism to $C_{2k+1}$. Until recently this classic observation had no analogue for $2k$-colorability. However, the development of homomorphisms and coloring of signed graphs has provided room for this and many other analogue studies. With a focus on 4-colorability, we consider the following extension of the "proper coloring" to signed graphs: a signed graph $(G, sigma)$ is said to be ${+1,-1,+2,-2}$-colorable if, using this set of colors, one can get a vertex-coloring $c$ satisfy ... 18:00 - 19:00 Physics Colloquium Uncovering Energetic Processes in the Interstellar/Intergalactic Medium with the Square Kilometre Array School PHYSICS Date and time Wednesday, 17 Farvardin 1401 (6th of April, 2022), 6 pm Link https://www.skyroom.online/ch/schoolofphysics/colloquium Abstract Investigating the physics and energetic of the medium where galactic structures, on various scales, are formed is the most fundamental step to understand the formation and evolution of galaxies. Modern galaxy evolution models suggest gas accretion from the intergalactic medium (IGM) or from cosmic filaments as a mechanism to maintain star formation and active galactic nucleus (AGN). Through ... |