Lower bounds on simple hash table operations? There are a variety of hash tables that support worst-case O(1)-time lookups and deletions and expected O(1)-time lookups. Is there a known lower-bound on hashing that says that there cannot be a hash table with (possibly amortized) worst-case O(1) lookups, insertions, and deletions?

Thanks!
The best known lower bounds are discussed in Thorup's "Mihai Pǎtraşcu: Obituary and Open Problems", and none preclude deterministic amortized constant-time operations.