Abstract
A subgroup G ≤ ℤω exhibits the Specker phenomenon if every homomorphism G → ℤ maps almost all unit vectors to 0. We give several combinatorial characterizations of the cardinal s-fraktur signe, the size of the smallest G ≤ ℤω exhibiting the Specker phenomenon. We also prove the consistency of b < e, where b is the unbounding number and e the evasion number. Our results answer several questions addressed by Blass.
Original language | English |
---|---|
Pages (from-to) | 19-27 |
Number of pages | 9 |
Journal | Journal of the London Mathematical Society |
Volume | 53 |
Issue number | 1 |
DOIs | |
State | Published - Feb 1996 |