We derive a “classical-quantum” approximation scheme for a broad class of bipartite quantum systems from fully quantum dynamics. In this approximation, one subsystem evolves via classical equations of motion with quantum corrections, and the other subsystem evolves quantum mechanically with equations of motion informed by the evolving classical degrees of freedom. Using perturbation theory, we...
We enter a concept that challenges conventional views on quantum particles by proposing a paradigm shift in the interpretations of their known behavior—introducing the concept of a continuous biphasic state with cyclically discontinuous states of matter. Inspired by advancements in relationalism theory that uses discrete signals rather than continuous motion for time, we delve into a thought...
Numerous experimental observations have demonstrated that fundamental charges are quantized. Consequently, point charge models are extensively applied in foundational physical theories such as electromagnetism and quantum field theory, achieving significant success.
However, electromagnetic theoretical calculations indicate that the energy of a point charge diverges, a phenomenon recognized...
In General Relativity, the ``ugly duckling'' of the Segre-Plebanski-Hawking-Ellis classification of stress-energy tensors (type III) is very difficult (and was believed to be impossible) to realise. Effective stress-energy tensors in alternative gravity cover a wider range of possibilities. We report a class of type III realisations in first-generation scalar-tensor and in Horndeski gravity,...
The KEYSTONE (KFPA Examinations of Young STellar Object Natal Environments) Survey observed ammonia gas toward 11 high-mass star-forming regions at distances of 0.7-2.7 kpc. Previous analysis of these data (Keown+, 2019) utilized a single line-of-sight velocity component in fitting the ammonia gas. Here we present results of a multiple-component fit to the same clouds over the NH3 (1,1)...
Finding a complete explanation for cosmological evolution in its very early stages (about 13 billion years ago) "can significantly advance our understanding of physics. Several models have been proposed, with the majority falling into a category called inflationary universes, where the universe experiences rapid exponential expansion. Despite numerous achievements of inflationary models in...
At the end of its evaporation, a black hole may leave a remnant where a large amount of information
is stored. We argue that the existence of an area gap as predicted by Loop Quantum Gravity removes
a main objection to this scenario. Remnants should radiate in the low-frequency spectrum. We
model this emission and derive properties of the diffuse radiation emitted by a population of...
We select two protostellar disks that are less than 500,000 years old, Oph IRS 63 and GSS 30 IRS 3, which have evidence of annular rings. For each disk, we use multi-wavelength, between 870 and 2000 microns, observations from ALMA to constrain disk models with and without rings using radiative transfer code, pdspy. We find that the models containing rings produce superior fits to both disks...
We present a general map from Poisson brackets to commutators, motivated by the Koopman-von Neumann formulation of classical mechanics. This map translates the entire apparatus of (Poisson bracket) classical mechanics to a quantum-like language, either in Hilbert space (operators and wavefunctions) or in phase space (star-products and Wigner functions). The setup can be interpreted as a...
A major challenge at the interface between quantum gravity and cosmology is to understand how cosmological structures can emerge from physics at the Planck scale. In this talk, I will provide a concrete example of such an emergence process by extracting the physics of scalar and isotropic cosmological perturbations from full quantum gravity, as described by a causally complete Barrett-Crane...
In pursuit of a full-fledged theory of quantum gravity, operational approaches offer insights into quantum-gravitational effects produced by quantum superposition of different spacetimes not diffeomorphic to one another. Recent work applies this approach to superpose cylindrically identified Minkowski spacetimes (i.e. periodic boundary conditions) with different characteristic circumferences,...
