Mathematics Problem Archive

Showing 101-150 of 2196 problems (Page 3 of 44)

AMR-018-0016
Open

Geometry of Continued Fractions — Sail statistics

v1.3 research notes

For every positive integer constant $C$ there exist only finitely many pairwise integer non-congruent faces with frequencies exceeding $C$....

L3
Geometry
AMR-018-0017
Open

Geometry of Continued Fractions — Sail statistics

v1.3 research notes

Is that true that sum of all relative frequencies for all possible faces is finite for higher dimensions $(n\ge 3)$?...

L3
Geometry
AMR-018-0018
Open

Geometry of Continued Fractions — Sail statistics

v1.3 research notes

In case of positive answer to the above question find the generalization of the Gauss map and compare the corresponding frequencies of faces with the ...

L3
Geometry
AMR-018-0021
Open

Geometry of Continued Fractions — Further open questions

v1.3 research notes

Study geometric properties of Markov spectrum....

L4
Geometry
AMR-019-0002
Open

Some Open Problems in Elasticity — Testing convexity conditions

v1.3 research notes

Find useful ways of verifying polyconvexity and quasiconvexity for stored-energy functions arising in anisotropic nonlinear elasticity....

L3
Partial Differential Equations
AMR-019-0003
Open

Some Open Problems in Elasticity — Regularity of minimizers

v1.3 research notes

Determine when the minimizer $y^*$ in Theorem 2.1 of the source is smooth....

L4
Partial Differential Equations
AMR-019-0006
Open

Some Open Problems in Elasticity — A positive Jacobian bound

v1.3 research notes

Prove or disprove that, under reasonable growth conditions on $W$, an energy-minimizing deformation satisfies $\det Dy^*(x)\ge\varepsilon>0$....

L3
Partial Differential Equations
AMR-019-0009
Open

Some Open Problems in Elasticity — Nonglobal local minimizers

v1.3 research notes

Devise general methods for proving the existence of local but nonglobal minimizers and other weak equilibria in nonlinear elastostatics....

L3
Partial Differential Equations
AMR-019-0013
Open

Some Open Problems in Elasticity — Qualitative dynamics

v1.3 research notes

Develop a qualitative dynamics for dynamic theories of elasticity....

L3
Partial Differential Equations
AMR-019-0015
Open

Some Open Problems in Elasticity — Atomistic foundations

v1.3 research notes

Establish the status of elasticity theory with respect to atomistic models....

L3
Partial Differential Equations
AMR-019-0017
Open

Some Open Problems in Elasticity — Elastic-crystal free energies

v1.3 research notes

For free-energy functions $\psi(A,\theta)$ of elastic crystals, determine boundary conditions under which the minimum is attained and conditions under...

L3
Partial Differential Equations
AMR-020-0201
Open

Open Problems in Integrable Systems — Topology of integrable systems, Lagrangian fibrations, and their invariants

v1.3 research notes

Under which additional assumptions does this principle become a rigorous theorem?...

L3
Dynamical Systems
AMR-020-0204
Open

Open Problems in Integrable Systems — Topology of integrable systems, Lagrangian fibrations, and their invariants

v1.3 research notes

Describe the symplectic invariants of stable rank-one singularities described by V. V. Kalashnikov. For such singularities, one of the action variable...

L3
Dynamical Systems
AMR-020-0209
Open

Open Problems in Integrable Systems — Topology of integrable systems, Lagrangian fibrations, and their invariants

v1.3 research notes

[N. T. Zung] Study the topology and geometry of these singular fibers and their small neighbourhoods....

L3
Dynamical Systems
AMR-020-0210
Open

Open Problems in Integrable Systems — Topology of integrable systems, Lagrangian fibrations, and their invariants

v1.3 research notes

[N. T. Zung] Give a clear description of these special singular fibers....

L3
Dynamical Systems
AMR-020-0301
Open

Open Problems in Integrable Systems — Two-dimensional case.

v1.3 research notes

Complete the above table: {\rm (1)} construct new examples of natural Hamiltonian systems on closed two-dimensional surfaces admitting polynomial inte...

L3
Dynamical Systems
AMR-020-0304
Open

Open Problems in Integrable Systems — Polynomial in momenta integrals in higher dimensions.

v1.3 research notes

Construct stationary axially symmetric 4-dimensional Einstein metrics admitting Killing tensors of higher order....

L3
Dynamical Systems
AMR-020-0305
Open

Open Problems in Integrable Systems — Polynomial in momenta integrals in higher dimensions.

v1.3 research notes

[Gilkey ] In the Riemannian case, is every $1$-homogeneous manifold locally homogeneous?...

L3
Dynamical Systems
AMR-020-0307
Open

Open Problems in Integrable Systems — Superintegrable systems

v1.3 research notes

{\it Construct a natural Hamiltonian system on the 2-sphere with a nonconstant potential which is superintegrable by integrals of degree $\ge 3$ and a...

L3
Dynamical Systems
AMR-020-0402
Open

Open Problems in Integrable Systems — Around the Birkhoff conjecture

v1.3 research notes

Prove the algebraic version of Birkhoff conjecture for outer billiards in a non-Euclidean surface of constant curvature....

L3
Dynamical Systems
AMR-020-0403
Open

Open Problems in Integrable Systems — Around the Birkhoff conjecture

v1.3 research notes

Prove Conjecture [source label: Descon] it the case that the foliation admits (i) a rational, (ii) an algebraic first integral....

L3
Dynamical Systems
AMR-020-0404
Open

Open Problems in Integrable Systems — Around the Birkhoff conjecture

v1.3 research notes

Is it possible to choose the domain so that the dynamics of the corresponding billiard map are locally (near the 2-periodic orbit) conjugated to the d...

L3
Dynamical Systems
AMR-020-0405
Open

Open Problems in Integrable Systems — Geometry of caustics, invariant surfaces, and commuting billiard maps

v1.3 research notes

Are there plane billiards, other than ellipses, that possess rational caustics with two different values of the rotation numbers? Same question for ou...

L3
Dynamical Systems
AMR-020-0409
Open

Open Problems in Integrable Systems — Noncommutative integrable maps

v1.3 research notes

{\rm (V. Retakh) Establish complete integrability of the noncommutative version of the leapfrog map. Define noncommutative versions of the pentagram m...

L3
Dynamical Systems
AMR-020-0501
Open

Open Problems in Integrable Systems — Bi-Poisson vector spaces

v1.3 research notes

Consider the action of $ Aut (V,J)$ on $V$. Describe the partition of $V$ into $ Aut (V,J)$-orbits. More generally, describe the action of $ Aut (V,J)...

L3
Dynamical Systems
AMR-020-0502
Open

Open Problems in Integrable Systems — Bi-Poisson vector spaces

v1.3 research notes

Find necessary and sufficient conditions for the bi-Lagrangian Grassmannian $LG(V,J)$ to be a smooth algebraic variety. Describe the partition of $LG(...

L3
Dynamical Systems
AMR-020-0503
Open

Open Problems in Integrable Systems — Bi-Poisson vector spaces

v1.3 research notes

Do bi-integrable systems exist for each algebraic type?...

L3
Dynamical Systems
AMR-020-0505
Open

Open Problems in Integrable Systems — Argument shift method and Jordan-Kronecker invariants of Lie algebras

v1.3 research notes

Are there any restrictions on the algebraic type of the pencils $\mathcal{A}_{x+\lambda a}$? Which algebraic types can be realised by means of an appr...

L3
Dynamical Systems
AMR-020-0506
Open

Open Problems in Integrable Systems — Argument shift method and Jordan-Kronecker invariants of Lie algebras

v1.3 research notes

Study examples of ``quadratic $+$ linear'' Poisson pencils. Compute their algebraic types and construct complete families of polynomials in bi-involut...

L3
Dynamical Systems
AMR-020-0507
Open

Open Problems in Integrable Systems — Argument shift method and Jordan-Kronecker invariants of Lie algebras

v1.3 research notes

Is it true that for any quadratic Poisson bracket (defined on a vector space), there exists a polynomial integrable system?...

L3
Dynamical Systems
AMR-020-0508
Open

Open Problems in Integrable Systems — Nijenhuis operators: singular points and global properties

v1.3 research notes

Describe closed manifolds $M$ which admit Nijenhuis operators $L(x)$ that are algebraically regular at each point $x\in M$....

L3
Dynamical Systems
AMR-020-0509
Open

Open Problems in Integrable Systems — Nijenhuis operators: singular points and global properties

v1.3 research notes

Let us fix a certain algebraic type of a linear operator, i.e., its Segre characteristic (see above). Does there exist a Nijenhuis operator $L$ in $\m...

L3
Dynamical Systems
AMR-020-0511
Open

Open Problems in Integrable Systems — Nijenhuis operators: singular points and global properties

v1.3 research notes

Describe all the functions $f(x,y)$ of two variables defined in a neighbourhood of $(0,0)\in\mathbb{R}^2$ such that ; $f_y(0,0)\not\equiv 0$; ; $f_y(0...

L3
Dynamical Systems
AMR-020-0512
Open

Open Problems in Integrable Systems — Nijenhuis operators: singular points and global properties

v1.3 research notes

Consider a smooth map $\Phi=(\sigma_1,\dots,\sigma_n): U(0) \to \mathbb{R}^n$, where $U(0)$ is a neighbourhood of the origin $0\in \mathbb{R}^n$. We a...

L3
Dynamical Systems
AMR-020-0513
Open

Open Problems in Integrable Systems — Nijenhuis operators: singular points and global properties

v1.3 research notes

Describe/classify the collections of algebraically independent homogeneous polynomials $\sigma_1, \dots, \sigma_n$, $\deg \sigma_k = k$, in $n$ variab...

L3
Dynamical Systems
AMR-020-0514
Open

Open Problems in Integrable Systems — Nijenhuis operators: singular points and global properties

v1.3 research notes

Describe the structure of singularities of $\Phi=(\sigma_1,\dots,\sigma_n): M \to \mathbb{R}^n$ in terms of the singular points of the recursion opera...

L3
Dynamical Systems
AMR-020-0604
Open

Open Problems in Integrable Systems — Poisson geometry and action-angle variables

v1.3 research notes

Which foliations with affine leaves can be described as the image of the moment map?...

L3
Dynamical Systems
AMR-020-0605
Open

Open Problems in Integrable Systems — Poisson geometry and action-angle variables

v1.3 research notes

Consider a Poisson manifold $M$ of even dimension such that it is symplectic on a dense set $U\subset M$. Assume that $M$ is endowed with a toric acti...

L3
Dynamical Systems
AMR-020-0702
Open

Open Problems in Integrable Systems — Integrability and Quantisation

v1.3 research notes

[S. V\ u Ng{\d o}c] Given a set of semiclassical operators that verify conditions [source label: item:self-adjoint ] and [source label: item:commute] ...

L3
Dynamical Systems
AMR-020-0704
Open

Open Problems in Integrable Systems — Integrability and Quantisation

v1.3 research notes

[S. V\ u Ng{\d o}c] Define (and detect) the quantum Chern class....

L3
Dynamical Systems
AMR-020-0709
Open

Open Problems in Integrable Systems — Integrability and Quantisation

v1.3 research notes

[\'{A}. Pelayo] Can one make progress in counting the number of fixed points by studying the spectrum of the quantisation of $\mu \colon M \to S^1$?...

L3
Dynamical Systems
AMR-020-0710
Open

Open Problems in Integrable Systems — Quantum integrability for polynomial in momenta integrals

v1.3 research notes

What are necessary and/or sufficient conditions on a metric $g$ such that every polynomial integral of its geodesic flow is quantisable?...

L3
Dynamical Systems
AMR-020-0712
Open

Open Problems in Integrable Systems — Integrable systems and geometric quantisation

v1.3 research notes

[Miranda-Presas-Solha ] Modify this scheme to get finite dimensional representation spaces for focus-focus and hyperbolic singularities that still cap...

L3
Dynamical Systems
AMR-021-0002
Open

Problems Around Polynomials — Conjecture 2

v1.3 research notes

[folklore, very irritating] For any set of charges of the same sign in $\mathbb{R}^n$, the set of its points of equilibrium is finite....

L3
Algebra
AMR-021-0003
Open

Problems Around Polynomials — Conjecture 3

v1.3 research notes

[A. Gabrielov, D. Novikov, B. Sh., seems good, but no progress] Let $(x_1,y_1),(x_2,y_2),\dots, (x_N,y_N)$ be a collection of points in $\mathbb{R}^2$...

L3
Algebra
AMR-021-0004
Open

Problems Around Polynomials — Problem 1

v1.3 research notes

[B. Sh., looks bad, but very important] Does there exist an upper bound for the number of real roots valid for all non-trivial solutions of all equati...

L3
Algebra
AMR-021-0005
Open

Problems Around Polynomials — Problem 2

v1.3 research notes

[D. Khavinson, I. Itenberg, B. Sh., apparently bad] Find the maximal possible number $\#(2k, l)$ of isolated zeros for real non-negative polynomials o...

L3
Algebra
AMR-021-0006
Open

Problems Around Polynomials — Problem 3

v1.3 research notes

[G. Ottaviani, B. Sh., seems good] Find the maximal possible number $\widetilde\#(2k, l)$ of isolated zeros for real non-negative polynomials of degre...

L3
Algebra
AMR-021-0007
Open

Problems Around Polynomials — Conjecture 4

v1.3 research notes

[G. Ottaviani, B. Sh., seems good] For any number of variables, $\widetilde\#(2k,l)=k^l$....

L3
Algebra
AMR-021-0008
Open

Problems Around Polynomials — Problem 4

v1.3 research notes

[S. Fisk, seems bad, see , p. 575] Given a pair of real polynomials $(p,q),$ give restrictions on the location of the roots of $p+iq$ in terms of the ...

L3
Algebra