435 research outputs found
A Note on Quantum Field Theories with a Minimal Length Scale
The aim of this note is to address the low energy limit of quantum field
theories with a minimal length scale. The essential feature of these models is
that the minimal length acts as a regulator in the asymptotic high energy limit
which is incorporated through an infinite series of higher order derivatives.
If one investigates a perturbative expansion in inverse powers of the Planck
mass, one generically obtains extra poles in the propagator, and instabilities
connected with the higher order derivative Lagrangian, that are however
artifacts of truncating the series
Bounds on an energy-dependent and observer-independent speed of light from violations of locality
We show that models with deformations of special relativity that have an
energy-dependent speed of light have non-local effects. The requirement that
the arising non-locality is not in conflict with known particle physics allows
us to derive strong bounds on deformations of special relativity and rule out a
modification to first order in energy over the Planck mass.Comment: short version of arXiv:0912.009
Phenomenological Quantum Gravity
Planck scale physics represents a future challenge, located between particle
physics and general relativity. The Planck scale marks a threshold beyond which
the old description of spacetime breaks down and conceptually new phenomena
must appear. In the last years, increased efforts have been made to examine the
phenomenology of quantum gravity, even if the full theory is still unknown.Comment: To appear in Proceedings of SUSY06, the 14th International Conference
on Supersymmetry and the Unification of Fundamental Interactions, UC Irvine,
California, 12-17 June 200
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