140 research outputs found
Testing the Master Constraint Programme for Loop Quantum Gravity V. Interacting Field Theories
This is the final fifth paper in our series of five in which we test the
Master Constraint Programme for solving the Hamiltonian constraint in Loop
Quantum Gravity. Here we consider interacting quantum field theories,
specificlly we consider the non -- Abelean Gauss constraints of Einstein --
Yang -- Mills theory and 2+1 gravity. Interestingly, while Yang -- Mills theory
in 4D is not yet rigorously defined as an ordinary (Wightman) quantum field
theory on Minkowski space, in background independent quantum field theories
such as Loop Quantum Gravity (LQG) this might become possible by working in a
new, background independent representation.Comment: 20 pages, no figure
Deformations of quantum field theories and integrable models
Deformations of quantum field theories which preserve Poincar\'e covariance
and localization in wedges are a novel tool in the analysis and construction of
model theories. Here a general scenario for such deformations is discussed, and
an infinite class of explicit examples is constructed on the Borchers-Uhlmann
algebra underlying Wightman quantum field theory. These deformations exist
independently of the space-time dimension, and contain the recently studied
warped convolution deformation as a special case. In the special case of
two-dimensional Minkowski space, they can be used to deform free field theories
to integrable models with non-trivial S-matrix.Comment: 36 pages, no figures: Minor changes and corrections in Section 3.
Added new Section 5 on von Neumann algebraic formulation, and modular
structur
The relativistic KMS condition for the thermal n-point functions of the P(φ)_2 model
Thermal quantum field theories are expected to obey a relativistic KMS condition, which replaces both the relativistic spectrum condition of Wightman quantum field theory and the KMS condition, which characterises equilibrium states in quantum statistical mechanics. In a previous work it has been shown that the two-point function of the thermal model satisfies the relativistic KMS condition. Here we extend this result to general -point functions
Temporal correlator in YM^2_3 and reflection-positivity violation
We consider numerical data for the lattice Landau gluon propagator obtained
at very large lattice volumes in three-dimensional pure SU(2) Yang-Mills gauge
theory (YM^2_3). We find that the temporal correlator C(t) shows an oscillatory
pattern and is negative for several values of t. This is an explicit violation
of reflection positivity and can be related to gluon confinement. We also
obtain a good fit for this quantity in the whole time interval using a sum of
Stingl-like propagators.Comment: 3 pages, 1 figure, 1 table, presented by A.R. Taurines at the IX
Hadron Physics and VII Relativistic Aspects of Nuclear Physics Workshops,
Angra dos Reis, Rio de Janeiro, Brazil (March 28--April 3, 2004
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