<ruby id="d9npn"></ruby>

<sub id="d9npn"><progress id="d9npn"></progress></sub>

<nobr id="d9npn"></nobr>

<rp id="d9npn"><big id="d9npn"><th id="d9npn"></th></big></rp>

<th id="d9npn"><meter id="d9npn"></meter></th>

# All Questions

152 questions
Filter by
Sorted by
Tagged with
59 views

### Proving Vizing's and Brooks' theorem using the polynomial approach

It is known that the graph polynomial defined by $\prod_{i<j}(x_i-x_j)$ where the vertices $x_k\ \ , \ \ k=\{1,2\ldots,n\}$ are ordered with respect to some order; can be used to verify the proper ...
116 views

### Graphs with Hermitian Unitary Edge Weights

Very recently, Hao Huang proved the Sensitivity Conjecture, which had been open for 30 years or so. Huang's proof is surprisingly short and easy. Here is Huang's preprint, a discussion on Scott ...
96 views

### Strong chromatic index of some cubic graphs

Edit 2019 June 26 New computer evidence forces us to revise our guesses relating strong chromatic index and girth Edit 2019 June 25 Some mistakes have been corrected. Question 2 has changed. ...
17 views

45 views

### Karp hardness of two cycles which lengths differ by one

Our problem is as follows: NEARLY-EQUAL-CYCLE-PAIR Input: An undirected graph $G(V,E)$ Output: YES if there exists $2$ (simple) cycles in $G$ which lengths differ by $1$, otherwise NO Is ...
138 views

### What is the complexity of counting Hamiltonian cycles of a graph?

Since deciding whether a graph contains a Hamiltonian cycle is $NP$-complete, the counting problem which counts the number of such cycles of a graph is $NP$-hard. Is it also $PP$-hard in the sense ...
109 views

### Does the problem of recognizing 3DORG-graphs have polynomial complexity?

A 2DORG is the intersection graph of a finite family of rays directed $\to$ or $\uparrow$ in the plane. Such graphs can be recognized effectively (Felsner et al.). A 3DORG is the intersection graph of ...
85 views

### Combinatorial region-halfplane incidence structures

I've seen a bunch of similar MO questions, yet hopefully this is not a complete duplicate. Consider $n$ halfplanes in $\mathbb{R}^2$ with their borders in general position, that is, no point of \$\...

15 30 50 per page
特码生肖图
<ruby id="d9npn"></ruby>

<sub id="d9npn"><progress id="d9npn"></progress></sub>

<nobr id="d9npn"></nobr>

<rp id="d9npn"><big id="d9npn"><th id="d9npn"></th></big></rp>

<th id="d9npn"><meter id="d9npn"></meter></th>

<ruby id="d9npn"></ruby>

<sub id="d9npn"><progress id="d9npn"></progress></sub>

<nobr id="d9npn"></nobr>

<rp id="d9npn"><big id="d9npn"><th id="d9npn"></th></big></rp>

<th id="d9npn"><meter id="d9npn"></meter></th>

5星时时缩水 新时时网易 现金棋牌捕鱼 体彩e球彩怎么看中奖 最新网络捕鱼游戏 河北20选5开奖结果 免费pk拾计划软件 燕赵风采20选5最新开奖 极速赛车冠军规律图 北京时时平台有哪些