Mathematics Problem Archive

Showing 301-350 of 381 problems (Page 7 of 8)

AMR-093-0059
Open

Characterize all algebraic number fields that have some power basis

v1.3 research notes

Characterize all algebraic number fields that have some power basis....

L4
Number Theory
AMR-093-0080
Open

Selberg's orthogonality conjecture

v1.3 research notes

Selberg's orthogonality conjecture: generalization of Mertens' theorem for functions in Selberg class....

L4
Number Theory
AMR-093-0104
Partially Solved

Wikipedia number-theory item 104: Congruent number problem (a corollary to Birch and Swinnerton-Dyer conjecture, per Tunnell's theorem…

v1.3 research notes

Congruent number problem (a corollary to Birch and Swinnerton-Dyer conjecture, per Tunnell's theorem): determine precisely what rational numbers are c...

L4
Number Theory
AMR-093-0120
Open

Dubner's conjecture

v1.3 research notes

Dubner's conjecture: every even number greater than $4208$ is the sum of two primes which both have a twin....

L4
Number Theory
AMR-094-0001
Partially Solved

Probabilistic McMillan theorem in higher dimensions

v1.3 research notes

Let $X_t$ be $d$-dimensional Brownian motion starting at the origin, let $D$ be an open subset of $\mathbb{R}^d$ containing the origin, and let $\tau=...

L4
Probability
AMR-094-0007
Partially Solved

Are shy couplings necessarily rigid?

v1.3 research notes

Let $D\subset\mathbb{R}^d$, $d\ge2$, be bounded, connected, and open. Suppose there are coupled reflected Brownian motions $X_t,Y_t$ in $D$ and $\vare...

L4
Probability
AMR-095-0001
Partially Solved

Stationary distributions in one dimension

v1.3 research notes

For the exclusion process on $\mathbb{Z}$ with $p(x,y)=p(y-x)$, assume $\sum_x|x|p(x)<\infty$, $\sum_xxp(x)>0$, and $\sum_{x<0}x^2p(x)=\infty$. Does t...

L4
Probability
AMR-095-0002
Open

Stationary distributions in higher dimensions

v1.3 research notes

On $\mathbb{Z}^2$, take nearest-neighbor jump probabilities $p_1,q_1,p_2,q_2$ in directions $\pm e_1,\pm e_2$, with $p_1>q_1$ and $p_2>q_2$. If the an...

L4
Probability
AMR-095-0003
Partially Solved

Exchangeability in the mean-zero exclusion process

v1.3 research notes

For the exclusion process on $\mathbb{Z}^d$ with translation-invariant kernel $p(x,y)=p(y-x)$ and zero mean $\sum_xxp(x)=0$, prove that every stationa...

L4
Probability
AMR-095-0004
Partially Solved

Negative association for asymmetric exclusion

v1.3 research notes

For nearest-neighbor asymmetric exclusion on $\mathbb{Z}$ with $p(1)=p>q=p(-1)$, start from the deterministic configuration $\cdots11110000\cdots$. Is...

L4
Probability
AMR-096-0037
Partially Solved

Topology and geometry of a self-similar random planar partition

v1.3 research notes

For Aldous's self-similar random partition of the plane, determine its topological properties: in particular, do region boundaries have fractal dimens...

L4
Probability
AMR-096-0038
Solved

Aldous-Lyons soficity conjecture

v1.3 research notes

Does every unimodular random countable locally finite rooted graph arise as a local weak limit of finite graphs?...

L4
Probability
AMR-098-0004
Solved

Exact coupling of singular non-discrete random walks

v1.3 research notes

Let $S$ and $S'$ be random walks on $\mathbb{R}$ with the same i.i.d. step-length distribution, starting at $0$ and $x$. Suppose the step lengths are ...

L4
Probability
AMR-098-0008
Partially Solved

Mass-stationarity of diffuse random measures via allocations

v1.3 research notes

Let $(X,\xi)$ consist of a random element and a diffuse random measure on a locally compact second countable Abelian group. Is mass-stationarity of $(...

L4
Probability
AMR-098-0009
Partially Solved

Markovian-kernel characterization of mass-stationarity

v1.3 research notes

Does the invariant-transport characterization of mass-stationarity remain valid if the bounded jointly invariant preserving kernels are restricted to ...

L4
Probability
AMR-099-0038
Partially Solved

Cheeger constant and the percolation nonuniqueness phase

v1.3 research notes

For every infinite vertex-transitive graph $G$, prove that $p_c(G)<p_u(G)$ if and only if $h(G)>0$....

L4
Probability
AMR-099-0086
Partially Solved

When is the uniqueness threshold below one?

v1.3 research notes

Give general conditions implying $p_u(G)<1$. In particular, prove or disprove that every one-ended transitive graph has $p_u(G)<1$....

L4
Probability
AMR-100-0001
Partially Solved

No percolation at the critical point on $\mathbb{Z}^d$

v1.3 research notes

For nearest-neighbor independent bond percolation on $\mathbb{Z}^d$, $d\ge2$, let $p_c(d)$ be the critical edge-retention probability. Prove that at $...

L4
Probability
AMR-105-0018
Open

Virtual-knot problem 18 — Wild Virtuals

v1.3 research notes

Wild Virtuals: Create the category of “wild virtual knots” and establish its axiomatics. In particular, one needs a theorem that states when a wild eq...

L4
Topology
AMR-105-0053
Partially Solved

Virtual-knot problem 53 — Is there any algorithm for recognition whether two graph-links are equivalent or not?

v1.3 research notes

Is there any algorithm for recognition whether two graph-links are equivalent or not? Our conjecture is “no”. The idea behind that is that graph-links...

L4
Topology
AMR-108-0052
Open

7.4 (Agol) — Algebraic trace fields of degenerate Kleinian groups

v1.3 research notes

Can there be a degenerate Kleinian group that is not the fiber of a fibration and has algebraic trace field?...

L4
Group Theory
AMR-108-0053
Open

7.5 (Schleimer) — Singly degenerate Kleinian groups over a number field

v1.3 research notes

Is there a singly degenerate Kleinian group for which all matrix entries of all group elements lie in one fixed number field?...

L4
Group Theory
AMR-109-0005
Partially Solved

Problem 3.1 — What is the smallest n = n(g) such that MCG (Sg) admits a properly dis- continuous action on Rn?

v1.3 research notes

What is the smallest n = n(g) such that MCG (Sg) admits a properly dis- continuous action on Rn? on a contractible n-manifold? (The answers are expect...

L4
Topology
AMR-109-0022
Partially Solved

Question 3.1 — (Fast word problem).

v1.3 research notes

(Fast word problem). Is there a sub-quadratic time algorithm to solve the word problem in Modg? One might guess that n logn is possible here, as there...

L4
Topology
AMR-109-0046
Open

Conjecture 4.8 — (Mod g is Kahler).

v1.3 research notes

(Mod g is Kahler). Forg≥ 3, the group Modg is a Kahler group, i.e. it is isomorphic to the fundamental group of a compact Kahler manifold. It was show...

L4
Topology
AMR-109-0058
Open

Conjecture 5.12 — Ig is finitely presented for g≥ 4.

v1.3 research notes

Ig is finitely presented for g≥ 4. One thing we do know is that, in contrast to Mod g, neither Ig norKg has a classifying space which is homotopy equi...

L4
Topology
AMR-109-0079
Open

Problem 7.3 — Compute L(Modg) explicitly for small g≥ 2.

v1.3 research notes

Compute L(Modg) explicitly for small g≥ 2. In principle L(Modg) can be computed for any given g. The point is that one can first bound the degree of L...

L4
Topology
AMR-109-0095
Open

Conjecture — Every subgroup of finite index in ModS contains a congruence subgroup.

v1.3 research notes

Every subgroup of finite index in ModS contains a congruence subgroup. V. Voevodsky had indicated (in a personal communication) a beautiful applicatio...

L4
Topology
AMR-109-0096
Open

Question I — s it true that any normal subgroup is commensurable with such a subgroup?

v1.3 research notes

s it true that any normal subgroup is commensurable with such a subgroup? Recall that two subgroups Γ 1, Γ2 of a group G are commensurable if the inte...

L4
Topology
AMR-109-0098
Solved

Conjecture I — f Γ is an irreducible arithmetic group of rank ≥ 2, then every homomorphism Γ→ ModS has finite image.

v1.3 research notes

f Γ is an irreducible arithmetic group of rank ≥ 2, then every homomorphism Γ→ ModS has finite image. For many arithmetic groups Γ the conjecture can ...

L4
Topology
AMR-109-0101
Open

Question — Does ModS has the Kazhdan property (T)?

v1.3 research notes

Does ModS has the Kazhdan property (T)? A positive answer would imply the positive answer to the previous question, but this problems seems to be much...

L4
Topology
AMR-109-0144
Solved

Problem 15 — [Ehrenpreis Conjecture] Given two closed Riemann surfaces, there are finite un- branched covers with homeomorphic tot…

v1.3 research notes

[Ehrenpreis Conjecture] Given two closed Riemann surfaces, there are finite un- branched covers with homeomorphic total spaces which are arbitrarily c...

L4
Topology
AMR-109-0172
Partially Solved

Problem 3.1 — Study, systematically and with the help of computers, the finite quotients of Mg which do not factor through Sp (2g, Z).

v1.3 research notes

Study, systematically and with the help of computers, the finite quotients of Mg which do not factor through Sp (2g, Z). We remark that Problem 3.1 wo...

L4
Topology
AMR-109-0174
Partially Solved

Problem 3.3 — Is there a faithful finite dimensional matrix representation of Mg,b,n for any value of the triplet (g,b,n ) other th…

v1.3 research notes

Is there a faithful finite dimensional matrix representation of Mg,b,n for any value of the triplet (g,b,n ) other than (1, 0, 0), (1, 1, 0), (1, 0, 1...

L4
Topology
AMR-109-0175
Partially Solved

Problem 3.4 — Find a candidate for a faithful finite-dimensional matrix representation of Mg orMg,1,0.

v1.3 research notes

Find a candidate for a faithful finite-dimensional matrix representation of Mg orMg,1,0....

L4
Topology
AMR-109-0184
Open

Problem 6 — Find special features of the monodromy of algebraic surfaces.

v1.3 research notes

Find special features of the monodromy of algebraic surfaces. There is some good motivation for this coming from at least three directions • The probl...

L4
Topology
AMR-109-0206
Partially Solved

Problem 7: — Is the mapping class group linear?

v1.3 research notes

Is the mapping class group linear? A locally compact group Γ is said to satisfy the Haagerup approximation property or is a-T- menable if there exists...

L4
Topology
AMR-109-0207
Open

Problem 8: — Is the mapping class group a-T-menable?

v1.3 research notes

Is the mapping class group a-T-menable? 14. Geometric properties of the mapping class group 245...

L4
Topology
AMR-109-0209
Open

Problem 2 — (Billiards in general polygons).

v1.3 research notes

(Billiards in general polygons). Does every billiard table have at least one regular periodic trajectory? If the answer is affirmative, does this trajec...

L4
Topology
AMR-109-0216
Solved

Problem 9 — (Orbit closures for moduli spaces).

v1.3 research notes

(Orbit closures for moduli spaces). Determine the closures of the orbits for the GL+(2, R)-action on H(α) andQ(β). Are these closures always complex-a...

L4
Topology
AMR-109-0243
Open

Question 1.1 — Forg≥ 2, does Γg contain a purely pseudo-Anosov surface subgroup?

v1.3 research notes

Forg≥ 2, does Γg contain a purely pseudo-Anosov surface subgroup? The paper is organized as follows. In §2, we discuss the existence of surface subgro...

L4
Topology
AMR-109-0244
Solved

Question 2.1 — Let M = H3/Γ be a finite volume hyperbolic 3-manifold, does Γ contain a surface subgroup.

v1.3 research notes

Let M = H3/Γ be a finite volume hyperbolic 3-manifold, does Γ contain a surface subgroup. This was answered in [ 8] for non-compact but finite volume ...

L4
Topology
AMR-109-0248
Open

Question 3.5 — LetH be a convex cocompact subgroup of Γg.

v1.3 research notes

LetH be a convex cocompact subgroup of Γg. Is Γg H-separable? Just focusing on surface subgroups, we can ask:...

L4
Topology
AMR-109-0250
Open

Question 4.1 — Does there exist a closed hyperbolic 4-manifold X that is the total space of a smooth fiber bundle Σg→X→ Σh?

v1.3 research notes

Does there exist a closed hyperbolic 4-manifold X that is the total space of a smooth fiber bundle Σg→X→ Σh? We will call such an X a surface bundle o...

L4
Topology
AMR-109-0252
Open

Conjecture 4.4 — Let M be a closed hyperbolic 4-manifold.

v1.3 research notes

Let M be a closed hyperbolic 4-manifold. Then all the Seiberg-Witten invariants of M vanish. The relevance of this is given in the following propositi...

L4
Topology
AMR-109-0254
Open

Question 4.7 — Forg,h≥ 2, does there exist a short exact sequence: 1→π1(Σg)→ Γ→π1(Σh)→ 1 for which Γ is a word hyperbolic group?

v1.3 research notes

Forg,h≥ 2, does there exist a short exact sequence: 1→π1(Σg)→ Γ→π1(Σh)→ 1 for which Γ is a word hyperbolic group? Arguing as in the proof of Theorem 4...

L4
Topology
AMR-109-0269
Open

Question 2.1 — Do mapping class groups or Out(Fn) satisfy the Baum-Connes conjecture?

v1.3 research notes

Do mapping class groups or Out(Fn) satisfy the Baum-Connes conjecture? Does Out(Fn) satisfy the Novikov conjecture? An approach to proving these conje...

L4
Topology
AMR-109-0272
Solved

Question 2.4 — Forn> 3, does Aut(Fn) have property (T)?

v1.3 research notes

Forn> 3, does Aut(Fn) have property (T)? The corresponding question for mapping class groups is also open. If Aut( Fn) were to have Property (T), then...

L4
Topology
AMR-109-0305
Open

Problem 3.2 — Determine whether the Torelli group Ig (g≥ 3) is finitely presentable or not (note that Ig (g≥ 3) is known to be fini…

v1.3 research notes

Determine whether the Torelli group Ig (g≥ 3) is finitely presentable or not (note that Ig (g≥ 3) is known to be finitely generated by Johnson [42])....

L4
Topology
AMR-110-0002
Open

Major problems 2 — The generating hypothesis, which asserts that the stable homotopy functor is faithful on the category…

v1.3 research notes

The generating hypothesis, which asserts that the stable homotopy functor is faithful on the category of finite spectra. That is, if f is a map of fin...

L4
Topology