منابع مشابه
Large quantum gravity effects and nonlocal variables
An interesting effect found recently, that points out to potential problems and/or surprises that could be found in quantum gravity, is the presence, in the quantization of certain midisuperspaces, of what has been called “large quantum gravity effects” (LE). In the original analysis of Ashtekar [1], the model chosen is rotationally symmetric 2+1 gravity coupled to a massless scalar field (a sp...
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The quantum theory of a free particle on a portion of two-dimensional Euclidean space bounded by a circle and subject to non-local boundary conditions gives rise to bulk and surface states. Starting from this well known property, a counterpart for gravity is here considered. In particular, if spatial components of metric perturbations are set to zero at the boundary, invariance of the full set ...
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Motivated by the conjecture that the cosmological constant problem is solved by strong quantum effects in the infrared we use the exact flow equation of Quantum Einstein Gravity to determine the renormalization group behavior of a class of nonlocal effective actions. They consist of the Einstein-Hilbert term and a general nonlinear function Fk(V ) of the Euclidean spacetime volume V . For the V...
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A nonlocal quantum gravity theory is presented which is finite and unitary to all orders of perturbation theory. Vertex form factors in Feynman diagrams involving gravitons suppress graviton and matter vacuum fluctuation loops by introducing a low-energy gravitational scale, ΛGvac < 2.4× 10−3 eV. Gravitons coupled to non-vacuum matter loops and matter tree graphs are controlled by a vertex form...
متن کاملEffective Nonlocal Euclidean Gravity
A nonlocal form of the effective gravitational action could cure the unboundedness of euclidean gravity with Einstein action. On sub-horizon length scales the modified gravitational field equations seem compatible with all present tests of general relativity and post-Newtonian gravity. They induce a difference in the effective Newton’s constant between regions of space with vanishing or nonvani...
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ژورنال
عنوان ژورنال: Modern Physics Letters A
سال: 1998
ISSN: 0217-7323,1793-6632
DOI: 10.1142/s0217732398003144