Unitarity in the Noncommutative Theories
نویسنده
چکیده
Simple argument in favour of unitarity, to all orders, of space-like noncommutative field theory is given. ∗supported by the grant no. 1 P03B 021 28 of Polish Minister of Science
منابع مشابه
Space-Time Noncommutative Field Theories And Unitarity
We study the perturbative unitarity of noncommutative scalar field theories. Field theories with space-time noncommutativity do not have a unitary S-matrix. Field theories with only space noncommutativity are perturbatively unitary. This can be understood from string theory, since space noncommutative field theories describe a low energy limit of string theory in a background magnetic field. On...
متن کاملTree Unitarity and Partial Wave Expansion in Noncommutative Quantum Field Theory
The validity of the tree-unitarity criterion for scattering amplitudes on the noncommutative space-time is considered, as a condition that can be used to shed light on the problem of unitarity violation in noncommutative quantum field theories when time is noncommutative. The unitarity constraints on the partial wave amplitudes in the noncommutative space-time are also derived.
متن کاملNoncommutative Dipole Field Theories And Unitarity
We extend the argument of Gomis and Mehen for violation of unitarity in field theories with space-time noncommutativity to dipole field theories. In dipole field theories with a timelike dipole vector, we present 1-loop amplitudes that violate the optical theorem. A quantum mechanical system with nonlocal potential of finite extent in time also shows violation of unitarity.
متن کاملCutting rules and perturbative unitarity of noncommutative electric-type field theories from string theory
We discuss the breakdown of perturbative unitarity of noncommutative quantum field theories in electric-type background in the light of string theory. We consider the analytic structure of string loop two-point functions and then perform the zero slope limit of Seiberg and Witten. In this way we pick up how the unphysical tachyonic branch cut appears in the effective field theory. We briefly di...
متن کاملQuantization of Space-time Noncommutative Theory
General aspects of the quantization of field theories non-local in time are discussed. The path integral on the basis of Schwinger’s action principle and the Bjorken-Johnson-Low prescription, which helps to recover the canonical structure from the results of the path integral, are used as the main machinery. A modified time ordering operation which formally restores unitarity in field theories ...
متن کامل