# Questions tagged [open-problems]

If it turns out that a problem is equivalent to a known open problem, then the open-problem tag is added. After that, the question essentially becomes, "What is known about this problem? What are some possible ways to approach this problem? What are some ways that people have tried to attack it before, and with what results?"

**7**

**2**answers

### What is known about polyhedra nets that allow overlapping?

**24**

**7**answers

### Convex hull in CAT(0)

**11**

**3**answers

### Motivation for uniform surjectivity of mod l representations associated to elliptic curves

**25**

**0**answers

### Milnor's cartography problem

**10**

**1**answer

### Is every matching of the hypercube graph extensible to a Hamiltonian cycle

**7**

**3**answers

### Is Murasugi's conjecture still open?

**12**

**0**answers

### Pencils with many completely decomposable fibers

**11**

**3**answers

### level sets of multivariate polynomials

**16**

**3**answers

### The Sylvester Gallai Theorem and Sections of Varieties with “Simple Topology”.

**21**

**4**answers

### Minimal surface in a ball

**6**

**1**answer

### Infinite dimensional Newlander-Nirenberg theorem

**11**

**2**answers

### Do torsion-free groups give projectionless group ($C^\ast$) algebras?

**31**

**1**answer

### Is the set of primes “translation-finite”?

**180**

**8**answers

### Two commuting mappings in the disk

**40**

**12**answers

### Can a discrete set of the plane of uniform density intersect all large triangles?

**10**

**2**answers

### A group action of the Heisenberg group with special symmetries

**0**

**3**answers

### Important (interesting) unsolved problems [closed]

**20**

**2**answers

### In a Banach algebra, do ab and ba have almost the same exponential spectrum?

**25**

**3**answers

### When does the converse to Schur's Lemma hold?

**8**

**3**answers

### Hamiltonian $S^1$ actions with isolated fixed points

**14**

**2**answers

### Is a smooth closed surface in Euclidean 3-space rigid?

**76**

**11**answers

### Is there a complex structure on the 6-sphere?

**19**

**5**answers

### Point singularity of a Riemannian manifold with bounded curvature

**18**

**4**answers

### Splitting Pythagorean triples

**7**

**0**answers

### Is there a finite-index finite-depth II$_1$ subfactor which is more than $7$-super-transitive?

**44**

**5**answers