Tackling Higher Derivative Ghosts with the Euclidean Path Integral

Abstract

An alternative to the effective field theory approach to treat ghosts in higher derivative theories is to attempt to integrate them out via the Euclidean path integral formalism. It has been suggested that this method could provide a consistent framework within which we might tolerate the ghost degrees of freedom that plague, among other theories, the higher derivative gravity models that have been proposed to explain cosmic acceleration. We consider the extension of this idea to treating a class of terms with order six derivatives, and find that for a general term the Euclidean path integral approach works in the most trivial background, Minkowski. Moreover we see that even in de Sitter background, despite some difficulties, it is possible to define a probability distribution for tensorial perturbations of the metric.

21 pages

References in corpus (14)

• The Effective Field Theory of Inflation
• Ghost Condensation and a Consistent Infrared Modification of Gravity
• Ghost Inflation
• Dilatonic ghost condensate as dark energy
• Living with Ghosts
• Constructing stabilized brane world models in five-dimensional Brans-Dicke theory
• Ghosts in the self-accelerating universe
• Generalized Gravity and a Ghost
• Ghost conditions for Gauss-Bonnet cosmologies
• Mimicking Lambda with a spin-two ghost condensate
• Giving up the ghost
• Tensor ghosts in the inflationary cosmology
• Where does Cosmological Perturbation Theory Break Down?
• Functional Determinants in Higher Derivative Lagrangian Theories

Cited by in corpus (9)

• Generalized Uncertainty Principle as a Consequence of the Effective Field Theory
• Screening of cosmological constant for De Sitter Universe in non-local gravity, phantom-divide crossing and finite-time future singularities
• Short distance modification of the quantum virial theorem
• On the one-loop effective potential in the higher-derivative four-dimensional chiral superfield theory with a nonconventional kinetic term
• On the one-loop effective potential in nonlocal supersymmetric theories
• On the decoupling of heavy states in higher-derivative supersymmetric field theories
• Renormalizing gravity: a new insight into an old problem
• Action with Acceleration I: Euclidean Hamiltonian and Path Integral
• Two-loop effective potential for general higher-derivative superfield models