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Quantum Gravity Demystified
One fruitful strategy of tackling quantum gravity is to adapt quantum field theory to the situation where spacetime geometry is dynamical, and to implement diffeomorphism symmetry in a way that...
Oct 27, 2022
Evaporating Black-to-White Hole
What is the ultimate fate of black holes? Since the discovery of Hawking evaporation process, the issue has been much discussed. Loop quantum gravity suggests that black hole could ultimately...
Oct 10, 2019
No entailing laws, but enablement in the evolution of the biosphere
Biological evolution is a complex blend of ever changing structural stability, variability and emergence of new phenotypes, niches, ecosystems. We wish to argue that the evolution of life marks the...
Oct 17, 2019
Gabriela González, Louisiana State University
Albert Einstein predicted a century ago the existence of gravitational waves – ripples in the fabric of spacetime moving at the speed of light. It was believed that these ripples...
Oct 23, 2019
Central extension in gravity
The asymptotic symmetry charge algebra of certain class of spacetimes could have a nontrivial central extension, which measures the non-equivariance of the charges of the large gauge transformations. The Cardy...
Oct 24, 2019
Dimensionally Restricted Causal Sets
We study dimensionally restricted non-perturbative causal set quantum dynamics in two and three spacetime dimensions with non-trivial global spatial topology. The causal set sample space is generated from causal embeddings...
Oct 31, 2019
Minimum length scenarios that maintain continuous symmetries
It has long been argued that combining the uncertainty principle with gravity will lead to an effective minimum length at the Planck scale. A particular challenge is to model the...
Nov 07, 2019
Planckian discreteness and dark energy phenomenology
I will explain how dark energy in cosmology could arise from the noisy diffusion of energy from the low energy degrees of freedom of matter (described in terms of QFT)...
Nov 13, 2019
Backreactions in Quantum Cosmological Perturbation Theory
Cosmological perturbation theory has a long tradition for describing the early phases of the Universe. As the observations of the CMB radiation suggest, it is reasonable, at least as a...
Nov 14, 2019
Planckian discreteness as a solution of Hawking's information puzzle
In approaches to quantum gravity, where smooth spacetime is an emergent approximation of a discrete Planckian fundamental structure, any standard effective field theoretical description will miss part of the degrees...
Nov 15, 2019