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Beneš Conjecture ★★★

Author(s): Beneš

Let $ E $ be a non-empty finite set. Given a partition $ \bf h $ of $ E $, the stabilizer of $ \bf h $, denoted $ S(\bf h) $, is the group formed by all permutations of $ E $ preserving each block of $ \mathbf h $.

Problem  ($ \star $)   Find a sufficient condition for a sequence of partitions $ {\bf h}_1, \dots, {\bf h}_\ell $ of $ E $ to be complete, i.e. such that the product of their stabilizers $ S({\bf h}_1) S({\bf h}_2) \dots S({\bf h}_\ell) $ is equal to the whole symmetric group $ \frak S(E) $ on $ E $. In particular, what about completeness of the sequence $ \bf h,\delta(\bf h),\dots,\delta^{\ell-1}(\bf h) $, given a partition $ \bf h $ of $ E $ and a permutation $ \delta $ of $ E $?
Conjecture  (Beneš)   Let $ \bf u $ be a uniform partition of $ E $ and $ \varphi $ be a permutation of $ E $ such that $ \bf u\wedge\varphi(\bf u)=\bf 0 $. Suppose that the set $ \big(\varphi S({\bf u})\big)^{n} $ is transitive, for some integer $ n\ge2 $. Then $$ \frak S(E) = \big(\varphi S({\bf u})\big)^{2n-1}. $$

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Geometry Dash Gold Coins Stars Cheats 2024 Update (FREE!!) ★★

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Geometry Dash Gold Coins Stars Cheats 2024 Update (FREE!!)

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3-accessibility of Fibonacci numbers ★★

Author(s): Landman; Robertson

Question   Is the set of Fibonacci numbers 3-accessible?

Keywords: Fibonacci numbers; monochromatic diffsequences

Coloring random subgraphs ★★

Author(s): Bukh

If $ G $ is a graph and $ p \in [0,1] $, we let $ G_p $ denote a subgraph of $ G $ where each edge of $ G $ appears in $ G_p $ with independently with probability $ p $.

Problem   Does there exist a constant $ c $ so that $ {\mathbb E}(\chi(G_{1/2})) > c \frac{\chi(G)}{\log \chi(G)} $?

Keywords: coloring; random graph

Fractional Hadwiger ★★

Author(s): Harvey; Reed; Seymour; Wood

Conjecture   For every graph $ G $,
(a) $ \chi_f(G)\leq\text{had}(G) $
(b) $ \chi(G)\leq\text{had}_f(G) $
(c) $ \chi_f(G)\leq\text{had}_f(G) $.

Keywords: fractional coloring, minors

Rainbow Six Siege Cheats Generator Unlimited R6 No Jailbreak (Premium Orginal Generator) ★★

Author(s):

Rainbow Six Siege Cheats Generator Unlimited R6 No Jailbreak (Premium Orginal Generator)

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¿Are critical k-forests tight? ★★

Author(s): Strausz

Conjecture  

Let $ H $ be a $ k $-uniform hypergraph. If $ H $ is a critical $ k $-forest, then it is a $ k $-tree.

Keywords: heterochromatic number

Are all Fermat Numbers square-free? ★★★

Author(s):

Conjecture   Are all Fermat Numbers \[ F_n  = 2^{2^{n } }  + 1 \] Square-Free?

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Hungry Shark Evolution Cheats Generator IOS Android No Survey 2024 (Generator!) ★★

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Hungry Shark Evolution Cheats Generator IOS Android No Survey 2024 (Generator!)

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Gta 5 Cheats Generator No Human Verification No Survey (Method 2024) ★★

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Gta 5 Cheats Generator No Human Verification No Survey (Method 2024)

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Dragon Ball Z Dokkan Battle Cheats Generator 2024 Update (FREE) ★★

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Dragon Ball Z Dokkan Battle Cheats Generator 2024 Update (FREE)

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Jaeger's modular orientation conjecture ★★★

Author(s): Jaeger

Conjecture   Every $ 4k $-edge-connected graph can be oriented so that $ {\mathit indegree}(v) - {\mathit outdegree}(v) \cong 0 $ (mod $ 2k+1 $) for every vertex $ v $.

Keywords: nowhere-zero flow; orientation

Covering a square with unit squares ★★

Author(s):

Conjecture   For any integer $ n \geq 1 $, it is impossible to cover a square of side greater than $ n $ with $ n^2+1 $ unit squares.

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The Crossing Number of the Complete Graph ★★★

Author(s):

The crossing number $ cr(G) $ of $ G $ is the minimum number of crossings in all drawings of $ G $ in the plane.

Conjecture   $ \displaystyle cr(K_n) =   \frac 14 \floor{\frac n2} \floor{\frac{n-1}2} \floor{\frac{n-2}2} \floor{\frac{n-3}2} $

Keywords: complete graph; crossing number

Graphs with a forbidden induced tree are chi-bounded ★★★

Author(s): Gyarfas

Say that a family $ {\mathcal F} $ of graphs is $ \chi $-bounded if there exists a function $ f: {\mathbb N} \rightarrow {\mathbb N} $ so that every $ G \in {\mathcal F} $ satisfies $ \chi(G) \le f (\omega(G)) $.

Conjecture   For every fixed tree $ T $, the family of graphs with no induced subgraph isomorphic to $ T $ is $ \chi $-bounded.

Keywords: chi-bounded; coloring; excluded subgraph; tree

Several ways to apply a (multivalued) multiargument function to a family of filters ★★★

Author(s): Porton

Problem   Let $ \mathcal{X} $ be an indexed family of filters on sets. Which of the below items are always pairwise equal?

1. The funcoid corresponding to this function (considered as a single argument function on indexed families) applied to the reloidal product of filters $ \mathcal{X} $.

2. The funcoid corresponding to this function (considered as a single argument function on indexed families) applied to the starred reloidal product of filters $ \mathcal{X} $.

3. $ \bigcap_{F\in\operatorname{up}^{\mathrm{FCD}}\prod^{\mathrm{Strd}}\mathcal{X}}\langle f \rangle F $.

Keywords: funcoid; function; multifuncoid; staroid

Ryser's conjecture ★★★

Author(s): Ryser

Conjecture   Let $ H $ be an $ r $-uniform $ r $-partite hypergraph. If $ \nu $ is the maximum number of pairwise disjoint edges in $ H $, and $ \tau $ is the size of the smallest set of vertices which meets every edge, then $ \tau \le (r-1) \nu $.

Keywords: hypergraph; matching; packing

Antichains in the cycle continuous order ★★

Author(s): DeVos

If $ G $,$ H $ are graphs, a function $ f : E(G) \rightarrow E(H) $ is called cycle-continuous if the pre-image of every element of the (binary) cycle space of $ H $ is a member of the cycle space of $ G $.

Problem   Does there exist an infinite set of graphs $ \{G_1,G_2,\ldots \} $ so that there is no cycle continuous mapping between $ G_i $ and $ G_j $ whenever $ i \neq j $ ?

Keywords: antichain; cycle; poset

World of Warships Cheats Generator Link 2024 (Cheats Generator that work) ★★

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World of Warships Cheats Generator Link 2024 (Cheats Generator that work)

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Free Clash of Clans Gems Cheats 2024 Edition Update (WORKS!) ★★

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Free Clash of Clans Gems Cheats 2024 Edition Update (WORKS!)

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PTAS for feedback arc set in tournaments ★★

Author(s): Ailon; Alon

Question   Is there a polynomial time approximation scheme for the feedback arc set problem for the class of tournaments?

Keywords: feedback arc set; PTAS; tournament

Working Generator World Of Tanks Blitz Gold Credits Cheats Android Ios 2024 (HOT) ★★

Author(s):

Working Generator World Of Tanks Blitz Gold Credits Cheats Android Ios 2024 (HOT)

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Legal* Free Coin Master Cheats Spins Coins Generator No Human Verification 2024 ★★

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Legal* Free Coin Master Cheats Spins Coins Generator No Human Verification 2024

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Simpsons Tapped Out Cheats Generator Unlimited Cheats Generator (New 2024) ★★

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Simpsons Tapped Out Cheats Generator Unlimited Cheats Generator (New 2024)

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Inequality of the means ★★★

Author(s):

Question   Is is possible to pack $ n^n $ rectangular $ n $-dimensional boxes each of which has side lengths $ a_1,a_2,\ldots,a_n $ inside an $ n $-dimensional cube with side length $ a_1 + a_2 + \ldots a_n $?

Keywords: arithmetic mean; geometric mean; Inequality; packing

Erdős-Posa property for long directed cycles ★★

Author(s): Havet; Maia

Conjecture   Let $ \ell \geq 2 $ be an integer. For every integer $ n\geq 0 $, there exists an integer $ t_n=t_n(\ell) $ such that for every digraph $ D $, either $ D $ has a $ n $ pairwise-disjoint directed cycles of length at least $ \ell $, or there exists a set $ T $ of at most $ t_n $ vertices such that $ D-T $ has no directed cycles of length at least $ \ell $.

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Unions of triangle free graphs ★★★

Author(s): Erdos; Hajnal

Problem   Does there exist a graph with no subgraph isomorphic to $ K_4 $ which cannot be expressed as a union of $ \aleph_0 $ triangle free graphs?

Keywords: forbidden subgraph; infinite graph; triangle free

eFootball 2023 Cheats Generator IOS Android No Verification 2024 (NEW STRATEGY) ★★

Author(s):

eFootball 2023 Cheats Generator IOS Android No Verification 2024 (NEW STRATEGY)

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Rise Of Kingdoms Cheats Generator 2023-2024 Edition (Verified) ★★

Author(s):

Rise Of Kingdoms Cheats Generator 2023-2024 Edition (Verified)

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Chromatic Number of Common Graphs ★★

Author(s): Hatami; Hladký; Kráľ; Norine; Razborov

Question   Do common graphs have bounded chromatic number?

Keywords: common graph

New Hungry Shark Evolution Cheats Generator Unlimited 2024 (NO FAKE AND NO SURVEY) ★★

Author(s):

New Hungry Shark Evolution Cheats Generator Unlimited 2024 (NO FAKE AND NO SURVEY)

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War Thunder Golden Eagles Generator Working Cheats (refreshed version) ★★

Author(s):

War Thunder Golden Eagles Generator Working Cheats (refreshed version)

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Decomposing eulerian graphs ★★★

Author(s):

Conjecture   If $ G $ is a 6-edge-connected Eulerian graph and $ P $ is a 2-transition system for $ G $, then $ (G,P) $ has a compaible decomposition.

Keywords: cover; cycle; Eulerian

Counterexamples to the Baillie-PSW primality test ★★

Author(s):

Problem  (1)   Find a counterexample to Baillie-PSW primality test or prove that there is no one.
Problem  (2)   Find a composite $ n\equiv 3 $ or $ 7\pmod{10} $ which divides both $ 2^{n-1} - 1 $ (see Fermat pseudoprime) and the Fibonacci number $ F_{n+1} $ (see Lucas pseudoprime), or prove that there is no such $ n $.

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New-mathod! Free Bloons TD Battles Energy Medal Money Cheats 2024 (No Human Verification) ★★

Author(s):

New-mathod! Free Bloons TD Battles Energy Medal Money Cheats 2024 (No Human Verification)

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Magic square of squares ★★

Author(s): LaBar

Question   Does there exist a $ 3\times 3 $ magic square composed of distinct perfect squares?

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Open problem ★★

Author(s):

Open problem

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Unit vector flows ★★

Author(s): Jain

Conjecture   For every graph $ G $ without a bridge, there is a flow $ \phi : E(G) \rightarrow S^2 = \{ x \in {\mathbb R}^3 : |x| = 1 \} $.

Conjecture   There exists a map $ q:S^2 \rightarrow \{-4,-3,-2,-1,1,2,3,4\} $ so that antipodal points of $ S^2 $ receive opposite values, and so that any three points which are equidistant on a great circle have values which sum to zero.

Keywords: nowhere-zero flow

Smooth 4-dimensional Schoenflies problem ★★★★

Author(s): Alexander

Problem   Let $ M $ be a $ 3 $-dimensional smooth submanifold of $ S^4 $, $ M $ diffeomorphic to $ S^3 $. By the Jordan-Brouwer separation theorem, $ M $ separates $ S^4 $ into the union of two compact connected $ 4 $-manifolds which share $ M $ as a common boundary. The Schoenflies problem asks, are these $ 4 $-manifolds diffeomorphic to $ D^4 $? ie: is $ M $ unknotted?

Keywords: 4-dimensional; Schoenflies; sphere

SimCity BuildIt Cheats Generator Free 2024 No Human Verification (New Update) ★★

Author(s):

SimCity BuildIt Cheats Generator Free 2024 No Human Verification (New Update)

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Apex Legends Coins Cheats 2024 (rejuvenated cheats) ★★

Author(s):

Apex Legends Coins Cheats 2024 (rejuvenated cheats)

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Cores of Cayley graphs ★★

Author(s): Samal

Conjecture   Let $ M $ be an abelian group. Is the core of a Cayley graph (on some power of $ M $) a Cayley graph (on some power of $ M $)?

Keywords: Cayley graph; core

Consecutive non-orientable embedding obstructions ★★★

Author(s):

Conjecture   Is there a graph $ G $ that is a minor-minimal obstruction for two non-orientable surfaces?

Keywords: minor; surface

Packing T-joins ★★

Author(s): DeVos

Conjecture   There exists a fixed constant $ c $ (probably $ c=1 $ suffices) so that every graft with minimum $ T $-cut size at least $ k $ contains a $ T $-join packing of size at least $ (2/3)k-c $.

Keywords: packing; T-join

War Thunder Unlimited Generator Golden Eagles Cheats IOS And Android No Survey 2024 (free!!) ★★

Author(s):

War Thunder Unlimited Generator Golden Eagles Cheats IOS And Android No Survey 2024 (free!!)

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Edge Reconstruction Conjecture ★★★

Author(s): Harary

Conjecture  

Every simple graph with at least 4 edges is reconstructible from it's edge deleted subgraphs

Keywords: reconstruction

Genshin Impact Generator Cheats without verification (Free) ★★

Author(s):

Genshin Impact Generator Cheats without verification (Free)

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World of Warships Cheats Generator Free Strategy 2024 (The Legit Method) ★★

Author(s):

World of Warships Cheats Generator Free Strategy 2024 (The Legit Method)

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The Sims Mobile Cheats Generator 2024 New Working Cheats Generator (New Method) ★★

Author(s):

The Sims Mobile Cheats Generator 2024 New Working Cheats Generator (New Method)

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Super Meat Boy Forever Points Cheats No Human Verification (Ios Android) ★★

Author(s):

Super Meat Boy Forever Points Cheats No Human Verification (Ios Android)

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