Mathematics Problem Archive

Showing 3301-3350 of 4271 problems (Page 67 of 86)

AMR-074-0122
Open

Lengths of Bounded-Rank Linear-Order WQOs

v1.3 research notes

For an ordinal $\alpha$, determine the length (maximal order type) of the well-quasi-order $L_\alpha$ of countable linear orders of Hausdorff rank bel...

L3
Logic
AMR-074-0124
Open

Strengths of Laver and Nash–Williams BQO Theorems

v1.3 research notes

Determine the reverse-mathematical strengths of Laver's labeled-linear-order theorem $\mathsf{LAV}$ and the Nash–Williams bqo transfinite-sequence the...

L3
Logic
AMR-074-0131
Open

Weak Infinitary Comprehension versus Weak Choice

v1.3 research notes

Is weak-$L_{\omega_1,\omega}$-$\mathsf{CA}$ equivalent to weak-$\Sigma^1_1$-$\mathsf{AC}_0$?...

L3
Logic
AMR-074-0204
Open

Open Mapping Theorem for Separable Banach Spaces

v1.3 research notes

Is the open mapping theorem for separable Banach spaces provable in $\mathsf{RCA}_0$, or at least in $\mathsf{WKL}_0$?...

L3
Logic
AMR-074-0205
Open

Strength of the Krein–Šmulian Theorem

v1.3 research notes

Determine the exact reverse-mathematical strength of the Krein–Šmulian theorem for separable Banach spaces....

L3
Logic
AMR-074-0208
Open

Strength of Szemerédi's Theorem

v1.3 research notes

Is Szemerédi's theorem provable in $\mathsf{ACA}_0$? More generally, determine its reverse-mathematical strength....

L3
Logic
AMR-074-0212
Open

Strength of Kříž's Labeled-Tree Theorem

v1.3 research notes

Determine the reverse-mathematical strength of Kříž's labeled-tree generalization of Kruskal's theorem....

L4
Logic
AMR-075-0012
Open

The universality spectrum problem

v1.3 research notes

The universality spectrum problem: Is there a first-order theory whose universality spectrum is minimum?...

L4
Logic
AMR-075-0016
Open

Does a finitely presented homogeneous structure for a finite relational language have finitely many reducts

v1.3 research notes

Does a finitely presented homogeneous structure for a finite relational language have finitely many reducts?...

L4
Logic
AMR-075-0021
Open

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 notes

Is the theory of the field of Laurent series over $\mathbb{Z}_p$ decidable? of the field of polynomials over $\mathbb{C}$?...

L4
Logic
AMR-075-0022
Open

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 notes

Is there a logic L which satisfies both the Beth property and Δ-interpolation, is compact but does not satisfy the interpolation property?...

L4
Logic
AMR-075-0024
Open

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 notes

What is the nature of the proof-theoretic ordinal (the smallest ordinal a theory cannot prove well-founded) for second-order arithmetic, ZFC, or stron...

L4
Logic
AMR-077-0006
Open

Meaning and Nonexistence of an Exact Three-Dimensional Ising Formula

v1.3 research notes

Give a mathematically precise meaning to an exact formula comparable to Onsager's formula for the two-dimensional Ising model, and prove or disprove t...

L4
Mathematical Physics
AMR-077-0011
Open

Short-Range Spin Glasses

v1.3 research notes

For 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...

L4
Mathematical Physics
AMR-077-0012
Open

Optimal Flux for the Quarter-Filled Band

v1.3 research notes

For the two-dimensional square-lattice model of independent electrons at density $1/4$, does magnetic flux $\pi/2$ per plaquette minimize the ground-s...

L3
Mathematical Physics
AMR-077-0013
Open

Bose-Einstein Condensation in Continuum Models

v1.3 research notes

Prove that Bose-Einstein condensation occurs in a continuum model of a weakly interacting Bose gas, or determine whether the long-held assertion fails...

L3
Mathematical Physics
AMR-078-0001
Open

Extended States in the Anderson Model

v1.3 research notes

Prove that the Anderson model has purely absolutely continuous spectrum in dimension $\nu\geq 3$, for suitable disorder width $b-a$, in some energy ra...

L3
Mathematical Physics
AMR-078-0002
Open

Localization in Two Dimensions

v1.3 research notes

Prove that the spectrum of the Anderson model in dimension $\nu=2$ is dense pure point....

L3
Mathematical Physics
AMR-078-0003
Open

Quantum Diffusion in the Anderson Model

v1.3 research notes

For the Anderson model in dimension $\nu\geq3$ and disorder strengths $|b-a|$ admitting absolutely continuous spectrum, prove that $\sum_{n\in\mathbb ...

L3
Mathematical Physics
AMR-078-0010
Open

Asymptotics of Atomic Ionization Energy

v1.3 research notes

For 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...

L3
Mathematical Physics
AMR-078-0011
Open

Mathematical Nuclear Shell Model

v1.3 research notes

Give a mathematically rigorous formulation and justification of the nuclear shell model....

L4
Mathematical Physics
AMR-078-0013
Open

Existence of Quantum Crystals

v1.3 research notes

Prove 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...

L4
Mathematical Physics
AMR-079-0004
Open

Painlev\'e equations

v1.3 research notes

What 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 ...

L3
Mathematical Physics
AMR-079-0010
Open

A Tracy-Widom Central Limit Theorem

v1.3 research notes

The 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...

L4
Mathematical Physics
AMR-080-0007
Open

additional problems for integrable systems

v1.3 research notes

In 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 - ...

L4
Mathematical Physics
AMR-080-0008
Open

Rigorous Diffraction from Two Slits

v1.3 research notes

Give a rigorous explicit solution of the fixed-frequency scalar-wave diffraction problem for two finite slits in the plane, including asymptotics of t...

L4
Mathematical Physics
AMR-081-0002
Open

Mutually Unbiased Bases in Dimension Six

v1.3 research notes

Construct a set of at least four mutually unbiased bases in dimension six, or prove that there are no seven mutually unbiased bases in $\mathcal{H}_6$...

L3
Mathematical Physics
AMR-081-0004
Open

Bound Entanglement with Negative Partial Transpose

v1.3 research notes

Determine whether there exist bound entangled bipartite quantum states with negative partial transpose....

L4
Mathematical Physics
AMR-083-0002
Open

O3 — Finding a prime above a bound

v1.3 research notes

Given $n\in\mathbb{N}$, can a prime $p>n$ be found in deterministic polynomial time?...

L3
Graph Theory
AMR-083-0003
Open

O4 — Finding a prime in an arithmetic progression

v1.3 research notes

Given coprime $a,n\in\mathbb{N}$, can a prime $p\equiv a\pmod n$ be found in deterministic polynomial time?...

L3
Graph Theory
AMR-083-0004
Open

O5a — Deterministic polynomial-time integer factorization

v1.3 research notes

Is complete integer factorization $C_5$ in deterministic polynomial time $P$?...

L3
Graph Theory
AMR-083-0005
Open

O5b — Randomized polynomial-time integer factorization

v1.3 research notes

Is complete integer factorization $C_5$ in randomized polynomial time $R$?...

L3
Graph Theory
AMR-083-0006
Open

O6 — Factoring a positive-density set of integers

v1.3 research notes

Does 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...

L3
Graph Theory
AMR-083-0007
Open

O7a — Computing the squarefree part

v1.3 research notes

Given $n$, can one find $r,s\in\mathbb{N}$ with $n=r^2s$ and $s$ squarefree in deterministic polynomial time?...

L3
Graph Theory
AMR-083-0008
Open

O7b — Factoring from a squarefree-part oracle

v1.3 research notes

Is complete integer factorization randomized polynomial-time reducible to computation of the squarefree part?...

L3
Graph Theory
AMR-083-0010
Open

O9 — Counting distinct prime factors

v1.3 research notes

Can $\omega(n)$, the number of distinct prime factors of $n$, be computed in deterministic polynomial time?...

L3
Graph Theory
AMR-083-0012
Open

O11a — Quadratic residuosity modulo a composite

v1.3 research notes

Can one decide in deterministic polynomial time whether a coprime integer $a$ is a square modulo a composite $n$?...

L3
Graph Theory
AMR-083-0013
Open

O11b — Factoring from composite quadratic residuosity

v1.3 research notes

Is complete integer factorization randomized polynomial-time reducible to deciding quadratic residuosity modulo a composite?...

L3
Graph Theory
AMR-083-0014
Open

O12 — Finding a quadratic nonresidue

v1.3 research notes

Given a prime $p$, can a quadratic nonresidue modulo $p$ be found in deterministic polynomial time?...

L3
Graph Theory
AMR-083-0015
Open

O13 — Realizing a prescribed quadratic signature

v1.3 research notes

Given 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...

L3
Graph Theory
AMR-083-0016
Open

O14 — Square roots modulo a prime

v1.3 research notes

Given a prime $p$ and a quadratic residue $a$, can a square root $x^2\equiv a\pmod p$ be found in deterministic polynomial time?...

L3
Graph Theory
AMR-083-0017
Open

O15 — Polynomial roots modulo a prime

v1.3 research notes

Given 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?...

L3
Graph Theory
AMR-083-0018
Open

O16 — Factoring polynomials modulo a prime

v1.3 research notes

Given 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?...

L3
Graph Theory
AMR-083-0020
Open

O18a — Recognizing primitive roots deterministically

v1.3 research notes

Given a prime $p$ and $b$, can one decide in deterministic polynomial time whether $b$ generates $(\mathbb{Z}/p\mathbb{Z})^*$?...

L3
Graph Theory
AMR-083-0021
Open

O18b — Recognizing primitive roots randomly

v1.3 research notes

Is recognition of primitive roots modulo a prime in randomized polynomial time $R$?...

L3
Graph Theory
AMR-083-0022
Open

O19 — Finding a primitive root modulo a prime

v1.3 research notes

Given a prime $p$, can a generator of $(\mathbb{Z}/p\mathbb{Z})^*$ be found in deterministic polynomial time?...

L3
Graph Theory
AMR-083-0023
Open

O20 — Computing multiplicative orders modulo a prime

v1.3 research notes

Given a prime $p$ and $a$ coprime to $p$, can $\operatorname{ord}_p(a)$ be computed in deterministic polynomial time?...

L3
Graph Theory
AMR-083-0024
Open

O21 — Discrete logarithms modulo a prime

v1.3 research notes

Given 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...

L3
Graph Theory
AMR-083-0025
Open

O22a — Discrete logarithms modulo a composite

v1.3 research notes

Given $g,b,n$ such that $g^x\equiv b\pmod n$ has a solution, can such an exponent $x$ be found in deterministic polynomial time?...

L3
Graph Theory
AMR-083-0029
Open

O25 — Solving binary quadratic congruences

v1.3 research notes

Given $k,m,n$ 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?...

L3
Graph Theory