Dear group,
The talk of Borivoje today at 1:30pm has been moved to our regular group
meeting tomorrow Friday at 2:30pm in M102. Here are the details of his talk,
Title: Probabilistic theories: Classical, Quantum and Beyond Quantum
Abstract:
Quantum theory makes the most accurate empirical predictions and yet it
lacks simple, comprehensible physical principles from which the theory can
be uniquely derived. A broad class of probabilistic theories exist which all
share some features with quantum theory, such as probabilistic predictions
for individual outcomes (indeterminism), the impossibility of information
transfer faster than speed of light (no-signaling) or the impossibility of
copying of unknown states (no-cloning). A vast majority of attempts to find
physical principles behind quantum theory either fall short of deriving the
theory uniquely from the principles or are based on abstract mathematical
assumptions that require themselves a more conclusive physical motivation.
Here, we show that classical probability theory and quantum theory can be
reconstructed from three reasonable axioms: (1) (Information capacity) All
systems with information carrying capacity of one bit are equivalent. (2)
(Locality) The state of a composite system is completely determined by
measurements on its subsystems. (3) (Reversibility) Between any two pure
states there exists a reversible transformation. If one requires the
transformation from the last axiom to be continuous, one separates quantum
theory from the classical probabilistic one. A remarkable result following
from our reconstruction is that no probability theory other than quantum
theory can exhibit entanglement without contradicting one or more axioms.
Cheers,
-A
--
Alejandro Perdomo-Ortiz
Ph.D. Candidate in Chemical Physics.
Harvard University
12 Oxford St #482, Cambridge, MA, 02138.
perdomo(a)fas.harvard.edu
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