Me, who is supposed to revise GCSE level maths for my mocks Random video explaining a maths concept I didn't even think could be thought up in fiction Me: hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
@ThoughtThrill3658 күн бұрын
They are unsolved for a reason 😄
@roy11gg5 күн бұрын
5:39 Kittler❤
@Busybody0077 күн бұрын
amazing animation soo easy to understand.
@davethesid89605 күн бұрын
0:18 - That's why in Hungarian we say "gráf" and "grafikon" to distinguish them.
@DeadJDona4 күн бұрын
9:30 what's the ratio of a sizes of triangles, adjacent to point for n-gon?
@patrickgambill93267 күн бұрын
9:58 What about the graph with no edges? Aren't the chromatic and total chromatic number the same?
@nivpearlman65147 күн бұрын
Delta(G)=0 X(G)=X''(G)=1 They are the same but trivially and equal to one
@patrickgambill93267 күн бұрын
Makes sense. I definitely misheard the video. They said maximum degree, not ordinary chromatic number 😅
@isavenewspapers88906 күн бұрын
This is an interesting edge case (no pun intended). For any edgeless graph, the chromatic number and the total chromatic number are either both 0 or both 1 (and hence the same number). The former arises only in the case of the unique graph with no vertices-the order-zero graph. After all, the graph vacuously starts out with every vertex and edge colored, so we don't need to pick up a single crayon. What about the maximum degree of this graph? Finding a graph's maximum degree amounts to finding the maximum of the set of the degrees of its vertices. But if you take the set of the degrees of the vertices of the order-zero graph, you just get the empty set. You can't take the maximum of the empty set, so the maximum degree of the order-zero graph is undefined. ... At least, I think that's how it works. For a more airtight answer, I'd probably need to be more careful about some of the formal definitions.
@marcelob.53007 күн бұрын
Great content!
@patrickgambill93267 күн бұрын
These are great! Do you like the switching reconstruction and vertex reconstruction problems?
@Dravignor7 күн бұрын
Where's the graph isomorphism problem?
@poland4m17s2 күн бұрын
What's that
@Dravignor2 күн бұрын
@@poland4m17s Say you have two "different" graphs, and you notice that for any two adjacent vertices/edges in the first graph, there is a corresponding pair of adjacent vertices/edges on the second one, such that you don't end up with any extra vertices/edges from one of them that doesn't correspond to anything from the other. You could think of this correspondence as a mapping that "preserves the structure" between the two. This is the idea of graph isomorphism. The Graph isomorphism problem seeks to automate the process of finding an isomorphism between any two graphs, and asks whether you can always determine whether such two graphs are isomorphic or not in a given amount of time (Specifically O(nᵏ) if you know computational time complexity).
@MooonheadКүн бұрын
@@Dravignor The question you are looking for would fit better into a theoretical computer science video. But it is certainly one of the easier algorithmic problems to explain and sits at an incredibly interesting spot in our current complexity landscape. Maybe he will make a video on TCS later on and include this problem? Edit: To be clear, I think you want him to address the problem of figuring out in which complexity class it sits right? Because simply solving the graph isomorphism problem is quite easy for any given instance if you don't care about time constraints.
@DravignorКүн бұрын
@Mooonhead Fair enough. Granted, I do not know much about graph theory; my only exposure to the subject was part of a rushed course in Discrete Math, but I was certainly interested in it at the time so I was hoping this video would bring more light into it. I do however appreciate your added clarity about the problem
@oserodal27026 күн бұрын
A category is just a funny graph with a few rules. Why not do unsolved problems for category theory?
@omfgacceptmyname6 күн бұрын
divine ambitions? really weird way to say that 5:15 this whole section was strange