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Agenesis of the right internal carotid artery with an unusual transsellar intracavernous intercarotid connection.
No full textAgenesis of the right internal carotid artery with an unusual transsellar intracavernous intercarotid connection.
No full text
New developments in the spectral asymptotics of quantum gravity
No full textA vanishing one-loop wave function of the Universe in the limit of small three-geometry is found, on imposing diffeomorphism-invariant boundary conditionson the Euclidean 4-ball in the de Donder gauge. This result suggests a quantum avoidance of the cosmological singularity driven by full diffeomorphism invariance of the boundary-value problem for one-loop quantum theory. All of this is made possible by a peculiar spectral cancellation on the Euclidean 4-ball, here derived and discussed
L'indagine radiologica nelle spondilodisciti conseguenti ad intervento per ernia del disco lombare
No full textSpectral methods in quantum field theory and quantum cosmology
No full textWe review the application of the spectral zeta function to the one-loop properties
of quantum field theories on manifolds with boundary, with emphasis on
Euclidean quantum gravity and quantum cosmology. As was shown in the
literature some time ago, the only boundary conditions that are completely
invariant under infinitesimal diffeomorphisms on metric perturbations suffer
from a drawback, i.e. lack of strong ellipticity of the resulting boundary value
problem. Nevertheless, at least on the Euclidean 4-ball background,
it remains possible to evaluate the ζ (0) value, which describes in this case
a universe which, in the limit of small 3-geometry, has vanishing probability
of approaching the cosmological singularity. An assessment of this result is
performed here, discussing its physical and mathematical implications
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