Mathematics Problem Archive
Some Questions — Question 28
v1.3 research notesDoes every infinite Cayley graph, or every infinite vertex-transitive graph, have a spanning tree without leaves?...
Some Questions — Question 29
v1.3 research notesIn every infinite Cayley graph, does the density of dead ends tend to zero?...
Some Questions — Question 30
v1.3 research notesAre factors of i.i.d. on the $3$-regular tree closed in the weak topology? In particular, is the weak limit of majority functions on $n$-balls a facto...
Some Questions — Question 33
v1.3 research notesFor every $k>1$, does there exist $C(k)<1$ such that the return probability of every transient $k$-regular Cayley graph is at most $C(k)$?...
Some Questions — Question 36
v1.3 research notesLet $(G_n)$ and $(H_n)$ converge to the same graph limit, and let $(T_n)$ be a convergent sequence with each $T_n$ a spanning tree of $G_n$. Do there ...
Some Questions — Question 37
v1.3 research notesLet $G$ be a bounded-degree expander, or strongly ergodic, graphing that can be properly colored by $C$ colors with arbitrarily small error. Can it be...
10 Lectures and 42 Open Problems — The planted clique problem
v1.3 research notesIs there a polynomial time algorithm that is able to find the largest clique of $G$ (with high probability) for $\omega \ll \sqrt{n}$ ? For example, f...
Visibility Graph Recognition
v1.3 research notesGiven a visibility graph $G$ and a Hamiltonian circuit $C$, determine in polynomial time whether there is a simple polygon whose vertex visibility gra...
3D Minimum-Bend Orthogonal Graph Drawings
v1.3 research notesDoes every simple graph with maximum vertex degree $\Delta \leq 6$ have a 3D orthogonal point-drawing with no more than two bends per edge? A 3D ortho...
Babai's problem
v1.3 research notesBabai's problem: which groups are Babai invariant groups?...
O3 — Finding a prime above a bound
v1.3 research notesGiven $n\in\mathbb{N}$, can a prime $p>n$ be found in deterministic polynomial time?...
O4 — Finding a prime in an arithmetic progression
v1.3 research notesGiven coprime $a,n\in\mathbb{N}$, can a prime $p\equiv a\pmod n$ be found in deterministic polynomial time?...
O5a — Deterministic polynomial-time integer factorization
v1.3 research notesIs complete integer factorization $C_5$ in deterministic polynomial time $P$?...
O5b — Randomized polynomial-time integer factorization
v1.3 research notesIs complete integer factorization $C_5$ in randomized polynomial time $R$?...
O6 — Factoring a positive-density set of integers
v1.3 research notesDoes there exist a set $S\subset\mathbb{N}$ of positive lower asymptotic density for which complete factorization of every input $n\in S$ is in determ...
O7a — Computing the squarefree part
v1.3 research notesGiven $n$, can one find $r,s\in\mathbb{N}$ with $n=r^2s$ and $s$ squarefree in deterministic polynomial time?...
O7b — Factoring from a squarefree-part oracle
v1.3 research notesIs complete integer factorization randomized polynomial-time reducible to computation of the squarefree part?...
O9 — Counting distinct prime factors
v1.3 research notesCan $\omega(n)$, the number of distinct prime factors of $n$, be computed in deterministic polynomial time?...
O11a — Quadratic residuosity modulo a composite
v1.3 research notesCan one decide in deterministic polynomial time whether a coprime integer $a$ is a square modulo a composite $n$?...
O11b — Factoring from composite quadratic residuosity
v1.3 research notesIs complete integer factorization randomized polynomial-time reducible to deciding quadratic residuosity modulo a composite?...
O12 — Finding a quadratic nonresidue
v1.3 research notesGiven a prime $p$, can a quadratic nonresidue modulo $p$ be found in deterministic polynomial time?...
O13 — Realizing a prescribed quadratic signature
v1.3 research notesGiven a sign vector $\varepsilon\in\{-1,1\}^k$, can the least prime $p$ satisfying $(p_i/p)=\varepsilon_i$ for every $i\le k$ be found in deterministi...
O14 — Square roots modulo a prime
v1.3 research notesGiven a prime $p$ and a quadratic residue $a$, can a square root $x^2\equiv a\pmod p$ be found in deterministic polynomial time?...
O15 — Polynomial roots modulo a prime
v1.3 research notesGiven a prime $p$ and $f\in(\mathbb{Z}/p\mathbb{Z})[x]$ known to have a root, can a root be found in deterministic polynomial time?...
O16 — Factoring polynomials modulo a prime
v1.3 research notesGiven a prime $p$ and $f\in(\mathbb{Z}/p\mathbb{Z})[x]$, can the complete irreducible factorization of $f$ be found in deterministic polynomial time?...
O18a — Recognizing primitive roots deterministically
v1.3 research notesGiven a prime $p$ and $b$, can one decide in deterministic polynomial time whether $b$ generates $(\mathbb{Z}/p\mathbb{Z})^*$?...
O18b — Recognizing primitive roots randomly
v1.3 research notesIs recognition of primitive roots modulo a prime in randomized polynomial time $R$?...
O19 — Finding a primitive root modulo a prime
v1.3 research notesGiven a prime $p$, can a generator of $(\mathbb{Z}/p\mathbb{Z})^*$ be found in deterministic polynomial time?...
O20 — Computing multiplicative orders modulo a prime
v1.3 research notesGiven a prime $p$ and $a$ coprime to $p$, can $\operatorname{ord}_p(a)$ be computed in deterministic polynomial time?...
O21 — Discrete logarithms modulo a prime
v1.3 research notesGiven a prime $p$ and elements $g,b$ with $b$ in the subgroup generated by $g$, can an exponent $x$ satisfying $g^x\equiv b\pmod p$ be found in determ...
O22a — Discrete logarithms modulo a composite
v1.3 research notesGiven $g,b,n$ such that $g^x\equiv b\pmod n$ has a solution, can such an exponent $x$ be found in deterministic polynomial time?...
O25 — Solving binary quadratic congruences
v1.3 research notesGiven $k,m,n$ with odd $n$ and $\gcd(km,n)=1$, can integers $x,y$ satisfying $x^2-ky^2\equiv m\pmod n$ be found in deterministic polynomial time?...
O26 — Discrete logarithm versus Diffie–Hellman key distribution
v1.3 research notesIs discrete logarithm modulo a prime randomized polynomial-time reducible to computing $g^{xy}$ from $g,g^x,g^y$?...
O27 — Elliptic curves of prescribed order
v1.3 research notesGiven a prime $p$ and $n$, can one construct in deterministic polynomial time an elliptic curve over $\mathbb{F}_p$ having exactly $n$ points whenever...
O28 — Discrete logarithms in elliptic-curve groups
v1.3 research notesGiven an elliptic curve over $\mathbb{F}_p$ and points $P,Q$ such that $P=nQ$ for some $n$, can such an $n$ be found in deterministic polynomial time?...
O34 — Solvability of the negative Pell equation
v1.3 research notesCan one decide in deterministic polynomial time whether $x^2-dy^2=-1$ has an integral solution?...
Absolute bounds for rational Diophantine tuples
v1.3 research notesIs there an absolute upper bound for the size of a rational Diophantine $m$-tuple, a set of nonzero rationals for which the product of every two disti...
Exceptional parameters without D(n)-quadruples
v1.3 research notesFor each $n\in\{-3,3,5,8,12,20\}$, prove that no set of four distinct positive integers has property $D(n)$, meaning that every pairwise product plus ...
Finiteness of parameters admitting at most two D(n)-quadruples
v1.3 research notesLet $U$ be the set of integers $n\not\equiv2\pmod4$ for which there are at most two distinct $D(n)$-quadruples. Is $U$ finite?...
Finiteness of D(n)-quadruples for nonsquare n
v1.3 research notesFor every nonzero integer $n$ that is not a square, are there only finitely many $D(n)$-quadruples?...
Triples having property D(n) for several parameters
v1.3 research notesAre there infinitely many Diophantine triples that are also $D(n)$-triples for three distinct integers $n\ne1$?...
Existence of a strong rational Diophantine quadruple
v1.3 research notesDoes there exist a set of four nonzero rational numbers $\{a_1,a_2,a_3,a_4\}$ such that $a_i a_j+1$ is a rational square for every $1\le i,j\le4$, inc...
Degree-only bounds for polynomial D(n)-tuples
v1.3 research notesLet $P_n$ be the supremum of the sizes of nondegenerate polynomial $D(n)$-tuples over $\mathbb{Z}[X]$. Find an upper bound for $P_n$ depending only on...
Problem 1.1
v1.3 research notesLet $f\in\mathbb{Z}[X,Y]$ be a polynomial such that the equation $f(x,y)=0$ has only finitely many solutions $(x,y)\in \mathbb{Z}\times\mathbb{Z}$. Gi...
Conjecture 1.4 — Shorey
v1.3 research notesThere exists a positive number $C$ which depends only on $L$ and $H$ with the following property. Let $m$, $x$ and $y$ be rational integers with $m\ge...
Conjecture 1.5
v1.3 research notesLet $k\ge 2$ be an integer and $\alpha_1,\ldots,\alpha_n$ be non-zero elements in a field $K$ of zero characteristic, such that no quotient $\alpha_i/...
Conjecture 1.7
v1.3 research notesIf there is no prime in the interval $[n+1,n+k]$, then the product $(n+1)\cdots(n+k)$ has at least $k$ distinct prime divisors....
Conjecture 1.8 — Langevin
v1.3 research notesGiven an increasing sequence $n_1<n_2<\cdots<n_k$ of positive integers such that $n_1,n_2,\ldots,n_k$ are multiplicatively dependent, there exists a p...
Conjecture 1.9
v1.3 research notesFix a positive integer $m$ for which the equation $$ m^2 + m_1^2 + m_2^2 = 3 mm_1m_2 $$ has a solution in positive integers $(m_1,m_2)$ with $0<m_1\le...
Conjecture 2.4 — Philippon
v1.3 research notesThere exist real numbers $\varepsilon$, $\alpha$ and $\beta$ with $0<\varepsilon<1/2$, $\alpha\ge 1$ and $\beta\ge 0$, and a positive integer $B$, suc...