# 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?"

**6**

**0**answers

### Tarski Monster group with prime 5

**5**

**0**answers

### Do the banded operators check the invariant subspace problem?

**3**

**1**answer

### Equiprojective polyhedra

**16**

**2**answers

### Tiling the square with rectangles of small diagonals

**18**

**2**answers

### Integer-distance sets

**9**

**1**answer

### Small quadrilaterals containing a given convex region

**45**

**0**answers

### Set-theoretic reformulation of the invariant subspace problem

**8**

**1**answer

### A question about the Axiom of Choice

**25**

**2**answers

### Open Problems in Algebraic Topology and Homotopy Theory

**11**

**1**answer

### A conjecture by Euler about $8n+3$

**2**

**0**answers

### Counting factors: is this approach in the literature on multiperfect numbers?

**5**

**1**answer

### List of open problems of formal languages [closed]

**2**

**2**answers

### Does this modified Hasse principle hold for curves?

**11**

**1**answer

### Needle probing for a convex body

**12**

**2**answers

### Distinctive property of the primes 17 and 19?

**1**

**2**answers

### A conjecture on closed discrete subset

**37**

**5**answers

### Surfaces filled densely by a geodesic

**32**

**12**answers

### Open problems in PDEs, dynamical systems, mathematical physics

**0**

**0**answers

### Known and unknown about Ramanujan's tau function

**3**

**1**answer

### Collatz conjecture— finite state machine transducer construction, origination?

**15**

**1**answer

### Is it true that every f.g. infinite simple group has exponential growth?

**10**

**4**answers

### problems from the scottish book

**7**

**1**answer

### Is there any o-minimal expansion of the real field with functions of growth higher than exponential?

**1**

**1**answer

### An open problem on general topology

**16**

**3**answers

### open problems in Seiberg-Witten Theory on 4-Manifolds

**7**

**0**answers

### How many values a polynomial map misses?

**17**

**1**answer

### Randomly switching street lights, in a square city

**12**

**7**answers

### Open problems in the theory of compact quantum groups

**12**

**4**answers

### What are the major open problems in design theory nowaday?

**20**

**2**answers

### Center of mass from the abstract point of view, or could the ancient Greeks invent modern analysis?

**27**

**4**answers

### Open problems in Birational Geometry, after BCHM

**10**

**1**answer

### Transcendentality of all irrationals in the Cantor set

**54**

**1**answer

### Intersecting Family of Triangulations

**47**

**1**answer

### A function whose fixed points are the primes

**15**

**2**answers

### Why Donaldson's Four-Six Conjecture?

**68**

**16**answers

### Important open problems that have already been reduced to a finite but infeasible amount of computation

**2**

**2**answers

### If all real conjugacy classes are strongly real, then all real irreps are “strongly real”(symmetric), true?

**5**

**1**answer

### Open problems about CMC hypersurfaces with symmetries?

**8**

**1**answer

### approximate uncertainty principle for finite abelian groups

**12**

**1**answer

### A maximal element, where Schur gives a minimal element

**11**

**1**answer

### Why would dim primitive irrep divide size of some conjugacy class ?

**14**

**3**answers

### Kaplansky's 6th conjecture: dim(Irrep) | dim(algebra) - for semi-simple Hopf algebras

**11**

**1**answer

### Are Galois groups of Q with restricted ramification supposed to be finitely generated?

**20**

**0**answers

### The oriented homeomorphism problem for Haken 3-manifolds

**8**

**0**answers

### Is $Q_n(x)=\sigma_{n+1}(x)/\sigma_n(x)$ logarithmically convex on $\mathbf{R}$?

**6**

**2**answers

### Measures of full Hausdorff dimension for self-affine sets

**9**

**3**answers

### Kronecker's Jugendtraum for real quadratic fields?

**11**

**1**answer

### The Class Number One Problem for Real Quadratic Fields

**3**

**2**answers

### S-matrix conjecture: status?

**14**

**1**answer