Mathematics Problem Archive
Lengths of Bounded-Rank Linear-Order WQOs
v1.3 research notesFor an ordinal $\alpha$, determine the length (maximal order type) of the well-quasi-order $L_\alpha$ of countable linear orders of Hausdorff rank bel...
Strengths of Laver and Nash–Williams BQO Theorems
v1.3 research notesDetermine the reverse-mathematical strengths of Laver's labeled-linear-order theorem $\mathsf{LAV}$ and the Nash–Williams bqo transfinite-sequence the...
Weak Infinitary Comprehension versus Weak Choice
v1.3 research notesIs weak-$L_{\omega_1,\omega}$-$\mathsf{CA}$ equivalent to weak-$\Sigma^1_1$-$\mathsf{AC}_0$?...
Open Mapping Theorem for Separable Banach Spaces
v1.3 research notesIs the open mapping theorem for separable Banach spaces provable in $\mathsf{RCA}_0$, or at least in $\mathsf{WKL}_0$?...
Strength of the Krein–Šmulian Theorem
v1.3 research notesDetermine the exact reverse-mathematical strength of the Krein–Šmulian theorem for separable Banach spaces....
Strength of Szemerédi's Theorem
v1.3 research notesIs Szemerédi's theorem provable in $\mathsf{ACA}_0$? More generally, determine its reverse-mathematical strength....
Strength of Kříž's Labeled-Tree Theorem
v1.3 research notesDetermine the reverse-mathematical strength of Kříž's labeled-tree generalization of Kruskal's theorem....
The universality spectrum problem
v1.3 research notesThe universality spectrum problem: Is there a first-order theory whose universality spectrum is minimum?...
Does a finitely presented homogeneous structure for a finite relational language have finitely many reducts
v1.3 research notesDoes a finitely presented homogeneous structure for a finite relational language have finitely many reducts?...
Is the theory of the field of Laurent series over $\mathbb{Z}_p$ decidable? of the field of polynomials over $\mathbb{C}$
v1.3 research notesIs the theory of the field of Laurent series over $\mathbb{Z}_p$ decidable? of the field of polynomials over $\mathbb{C}$?...
Is there a logic L which satisfies both the Beth property and Δ-interpolation, is compact but does not satisfy the interpolation property
v1.3 research notesIs there a logic L which satisfies both the Beth property and Δ-interpolation, is compact but does not satisfy the interpolation property?...
Wikipedia model theory and formal languages item 24: What is the nature of the proof-theoretic ordinal (the smallest ordinal a theory cannot prove w…
v1.3 research notesWhat is the nature of the proof-theoretic ordinal (the smallest ordinal a theory cannot prove well-founded) for second-order arithmetic, ZFC, or stron...
Meaning and Nonexistence of an Exact Three-Dimensional Ising Formula
v1.3 research notesGive a mathematically precise meaning to an exact formula comparable to Onsager's formula for the two-dimensional Ising model, and prove or disprove t...
Short-Range Spin Glasses
v1.3 research notesFor the Edwards-Anderson Ising spin glass on $\mathbb{Z}^d$ with i.i.d. mean-zero finite-variance nearest-neighbor couplings, prove or disprove the ex...
Optimal Flux for the Quarter-Filled Band
v1.3 research notesFor the two-dimensional square-lattice model of independent electrons at density $1/4$, does magnetic flux $\pi/2$ per plaquette minimize the ground-s...
Bose-Einstein Condensation in Continuum Models
v1.3 research notesProve that Bose-Einstein condensation occurs in a continuum model of a weakly interacting Bose gas, or determine whether the long-held assertion fails...
Extended States in the Anderson Model
v1.3 research notesProve that the Anderson model has purely absolutely continuous spectrum in dimension $\nu\geq 3$, for suitable disorder width $b-a$, in some energy ra...
Localization in Two Dimensions
v1.3 research notesProve that the spectrum of the Anderson model in dimension $\nu=2$ is dense pure point....
Quantum Diffusion in the Anderson Model
v1.3 research notesFor the Anderson model in dimension $\nu\geq3$ and disorder strengths $|b-a|$ admitting absolutely continuous spectrum, prove that $\sum_{n\in\mathbb ...
Asymptotics of Atomic Ionization Energy
v1.3 research notesFor the $N$-electron Coulomb ground-state energy $E(N,Z)$, determine the asymptotics of the ionization energy $\delta E(Z)=E(Z,Z-1)-E(Z,Z)$ as $Z\to\i...
Mathematical Nuclear Shell Model
v1.3 research notesGive a mathematically rigorous formulation and justification of the nuclear shell model....
Existence of Quantum Crystals
v1.3 research notesProve that, as the number of nuclei tends to infinity, the ground state of some neutral system of nuclei and electrons approaches a periodic limit, es...
Painlev\'e equations
v1.3 research notesWhat I have in mind here is not a specific problem, but a project, a very large scale project. The six (nonlinear) Painlev\'e equations form the core ...
A Tracy-Widom Central Limit Theorem
v1.3 research notesThe fact that RMT, and the Tracy-Widom distributions, arise in so many problems in so many different areas leads one to the following question: how ca...
additional problems for integrable systems
v1.3 research notesIn 2002, P. Zhou analyzed the behavior of solutions of the Cauchy problem for perturbations of the defocusing NLS equation i u_t + u_{xx}- 2|u|^2 u - ...
Rigorous Diffraction from Two Slits
v1.3 research notesGive a rigorous explicit solution of the fixed-frequency scalar-wave diffraction problem for two finite slits in the plane, including asymptotics of t...
Mutually Unbiased Bases in Dimension Six
v1.3 research notesConstruct a set of at least four mutually unbiased bases in dimension six, or prove that there are no seven mutually unbiased bases in $\mathcal{H}_6$...
Bound Entanglement with Negative Partial Transpose
v1.3 research notesDetermine whether there exist bound entangled bipartite quantum states with negative partial transpose....
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?...