2007/08/07 by Gavinsky, Dmytro, Pudlák, Pavel
#FOS: Physical sciences #Quantum Physics (quant-ph)
paper · doi:10.48550/arxiv.0708.0859
We give the first exponential separation between quantum and classical multi-party communication complexity in the (non-interactive) one-way and simultaneous message passing settings. For every k, we demonstrate a relational communication problem between k parties that can be solved exactly by a quantum simultaneous message passing protocol of cost O(log n) and requires protocols of cost nc/k2, where c>0 is a constant, in the classical non-interactive one-way message passing model with shared randomness and bounded error. Thus our separation of corresponding communication classes is superpolynomial as long as k=o(√(log n / loglog n)) and exponential for k=O(1).