6 papers · 1 filter
Potential theory and forcing
Jindrich Zapletal
We isolate a combinatorial property of capacities leading to a construction of proper forcings. Then we show that many classical capacities such as the Newtonian capacity satisfy t…
Two preservation theorems
Jindrich Zapletal
I prove preservation theorems for countable support iteration of proper forcing concerning certain classes of capacities and submeasures. New examples of forcing notions and connec…
Forcing with quotients
Michael Hrusak, Jindrich Zapletal
We study an extensive connection between factor forcings of Borel subsets of Polish spaces modulo a sigma-ideal, and factor forcings of subsets of countable sets modulo an ideal.
Between Maharam's and von Neumann's problems
Ilijas Farah, Jindrich Zapletal
If I is a suitably definable sigma-ideal on the real line and the factor algebra of Borel sets modulo I is weakly distributive then the algebra carries a Maharam submeasure.
On the structure of stationary sets
Q. Feng, T. Jech, J. Zapletal
We isolate several classes of stationary sets of kappa^omega and investigate implications among them. Under a large cardinal assumption, we prove a structure theorem for stationary…
Proper forcing and rectangular Ramsey theorems
Jindrich Zapletal
I prove forcing preservation theorems for products of definable partial orders preserving the cofinality of the meager or null ideal. Rectangular Ramsey theorems for related ideals…