clopen.solutions

Open problems

980 registered problems.

OP-00337 Open
Costas arrays at every order
CO · AIM Open Applied Problems · Costas arrays · permutation arrays
OP-00338 Open
Classifying Costas polynomials over extension fields
NT · AIM Open Applied Problems · Costas polynomials · finite fields · permutation polynomials
OP-00367 Solution claimed
Smallest orders for periodic multidimensional Costas arrays
CO · AIM Open Applied Problems · Costas arrays · permutation arrays
OP-00551 Solution claimed
Sharp exponential cost of fast boundary quantum control
OC · AIM Open Applied Problems · control costs · null controllability · Schrödinger equations
OP-00973 Open
Cost of a group and its first ℓ²-Betti number
GR · cost · ℓ²-Betti numbers · measured group theory · Peterson's operator algebra problems