# 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?"

**13**

**2**answers

### Torsion-freeness of two groups with 2 generators and 3 relators and Kaplansky Zero Divisor Conjecture

**2**

**1**answer

### A generalization of Frankl's conjecture?

**21**

**3**answers

### Open problems in Hopf algebras

**3**

**1**answer

### If $N = qn^2$ is an odd perfect number with $\gcd(q,n)=1$, is it possible to have $q + 1 = \sigma(n)$?

**1**

**0**answers

### The complexity of Max-K interval selection

**9**

**1**answer

### A strengthening of Frankl's union-closed sets conjecture?

**2**

**1**answer

### Why is Kronecker's Jugendtraum only for abelian extensions?

**51**

**9**answers

### What are some important but still unsolved problems in mathematical logic?

**7**

**0**answers

### Does every model of $I\Delta_0$ has an end extension to a model of $I\Delta_0+\Omega_1$?

**11**

**1**answer

### Some Questions on the Collatz conjecture (reexpressed as “equivalence relation”)

**11**

**2**answers

### Open Problems for Undergraduates [closed]

**-4**

**2**answers

### Diagonal argument for even perfect numbers

**13**

**1**answer

### On cubic reciprocity for $x^3+y^3+z^3 = 996$?

**7**

**1**answer

### What are some open problems regarding elliptic curves in finite fields?

**6**

**1**answer

### Open questions on (finite) tensor categories

**19**

**3**answers

### All compact surfaces $S\subseteq \mathbb{R}^3$ are rigid?

**1**

**2**answers

### Looking for (information about) long diamonds

**4**

**0**answers

### What is behind the Hodge conjecture? [duplicate]

**154**

**30**answers

### Proposals for polymath projects

**12**

**0**answers

### Progress in Guy's “Unsolved problems in Number Theory”? [closed]

**5**

**1**answer

### A variant of Freiling's Axiom of Symmetry and a weak form of the Continuum Hypothesis in models where all sets of reals are Lebesgue measurable

**12**

**2**answers

### Gerstenhaber conjecture for free loop space

**9**

**0**answers

### Bang's open question strengthening Tarski's planks problem

**4**

**1**answer

### Sets not containing the vertices of unit triangles (Question posed by Erdős)

**6**

**0**answers

### Functions on [0,1] with positive fractional series coefficients and symmetric under x->1-x

**6**

**1**answer

### Conway's subprime Fibonacci sequences

**21**

**1**answer

### Why is it so hard to prove Toeplitz' conjecture?

**2**

**0**answers

### Newer list of open problems in model theory

**7**

**2**answers

### Open problems in hyperplane/subspace arrangements?

**3**

**1**answer

### Open problems books [closed]

**5**

**1**answer

### Open problems in Banach spaces, universality

**16**

**8**answers

### Open problems in continued fractions theory

**15**

**2**answers

### *The* open problem in General Relativity?

**4**

**0**answers

### What is the status on questions related to Bhargava's factorial function?

**2**

**0**answers

### On Descartes / spoof odd perfect numbers

**2**

**0**answers

### Are there any interesting open questions having to do with submodularity, specially in the intersection of theoretical machine learning? [closed]

**1**

**1**answer

### Reference request: Research done on whether the Euler prime can be the largest factor of an odd perfect number

**9**

**2**answers

### Can any finite lattice be realized as an intermediate subgroups lattice?

**18**

**2**answers

### Open problems in Berkovich geometry

**21**

**5**answers

### Collection of conjectures and open problems in graph theory

**5**

**1**answer

### Ruth-Aaron triples, etc

**3**

**1**answer

### Open problems in compressed sensing

**18**

**1**answer

### Is every projective space curve a set-theoretic intersection of two surfaces? What is known about this question?

**2**

**0**answers

### Long paths in the supercritical percolation.

**4**

**0**answers

### Reduction argument from a general vertex set V(G) to a prime power in Prof. Keevash's proof on the Existence of Designs

**6**

**1**answer

### Inverted pair of complex analytic families

**9**

**0**answers

### Randomly placing nonoverlapping unit cuboids

**2**

**3**answers

### Gauss Codes that produce classical knots as opposed to virtual knots

**16**

**0**answers

### Does $S^4$ have a “symplecto-homeomorphic” structure?

**37**

**3**answers