scholarly journals New perspective on matter coupling in 2D quantum gravity

1999 ◽  
Vol 60 (10) ◽  
Author(s):  
J. Ambjørn ◽  
K. N. Anagnostopoulos ◽  
R. Loll
2012 ◽  
Vol 27 (07) ◽  
pp. 1250032 ◽  
Author(s):  
FRANCESCO CIANFRANI ◽  
GIOVANNI MONTANI

This papers offers a critical discussion on the procedure by which Loop Quantum Cosmology (LQC) is constructed from the full Loop Quantum Gravity (LQG) theory. Revising recent issues in preserving SU(2) symmetry when quantizing the isotropic Universe, we trace a new perspective in approaching the cosmological problem within quantum geometry. The cosmological sector of LQG is reviewed and a critical point of view on LQC is presented. It is outlined how a polymer-like scale for quantum cosmology can be predicted from a proper fundamental graph underlying the homogeneous and isotropic continuous picture. However, such a minimum scale does not coincide with the choice made in LQC. Finally, the perspectives towards a consistent cosmological LQG model based on such a graph structure are discussed.


2016 ◽  
Vol 25 (13) ◽  
pp. 1645010 ◽  
Author(s):  
Hyun Seok Yang

We emphasize that noncommutative (NC) spacetime necessarily implies emergent spacetime if spacetime at microscopic scales should be viewed as NC. In order to understand NC spacetime correctly, we need to deactivate the thought patterns that we have installed in our brains and taken for granted for so many years. Emergent spacetime allows a background-independent formulation of quantum gravity that will open a new perspective to resolve the notorious problems in theoretical physics such as the cosmological constant problem, hierarchy problem, dark energy, dark matter and cosmic inflation.


1996 ◽  
Vol 111 (12) ◽  
pp. 1405-1414
Author(s):  
M. Carmeli ◽  
S. Malin

2020 ◽  
Author(s):  
Stephane Maes

We start from a hypothetical multi-fold universe U_{MF}}, where the propagation of everything is slower or equal to the speed of light and where entanglement extends the set of paths available to Path Integrals. This multi-fold mechanism enables EPR (Einstein-Podolsky-Rosen) “spooky actions at distance” to result from local interactions in the resulting folds. It produces gravity-like attractive effective potentials in the spacetime, between entangled entities, that are caused by the curvature of the folds. When quantized, multi-folds correspond to gravitons and they are enablers of EPR entanglement. Gravity emerges non-perturbative and covariant from EPR entanglement between virtual particles surrounding an entity.In U_{MF}, we encounter mechanisms that predict gravity fluctuations when entanglement is present, including in macroscopic entanglements. Besides providing a new perspective on quantum gravity, when added to the Standard Model and Standard Cosmology, U_{MF} can contribute explanations of several open questions and challenges. It also clarifies some relationships and challenges met by other quantum gravity models and Theories of Everything. It leads to suggestions for these works.We also reconstruct the spacetime of U_{MF}, starting from the random walks of particles in an early spacetime. U_{MF} now appears as a noncommutative, discrete, yet Lorentz symmetric, spacetime that behaves roughly 2-Dimensional at Planck scales, when it is a graph of microscopic Planck size black holes on a random walk fractal structure left by particles that can also appear as also microscopic black holes. Of course, at larger scales, spacetime appears 4-D, where we are able to explain curvature and recover Einstein’s General Relativity. We also discover an entanglement gravity-like contributions and massive gravity at very small scales. This is remarkable considering that no Hilbert Einstein action, or variations expressing area invariance, were introduced. Our model also explains why semi classical approaches can work till way smaller scale than usually expected and present a new view on an Ultimate Unification of all forces, at very small scales.We also explore opportunities for falsifiability and validation of our model, as well as ideas for futuristic applications that may be worth considering, if U_{MF} was a suitable model for our universe U_{real}.


Author(s):  
H.-J. Ou

The understanding of the interactions between the small metallic particles and ceramic surfaces has been studied by many catalyst scientists. We had developed Scanning Reflection Electron Microscopy technique to study surface structure of MgO hulk cleaved surface and the interaction with the small particle of metals. Resolutions of 10Å has shown the periodic array of surface atomic steps on MgO. The SREM observation of the interaction between the metallic particles and the surface may provide a new perspective on such processes.


1979 ◽  
Vol 10 (3) ◽  
pp. 145-151 ◽  
Author(s):  
Sallie W. Hillard ◽  
Laura P. Goepfert

This paper describes the concept of teaching articulation through words which have inherent meaning to a child’s life experience, such as a semantically potent word approach. The approach was used with six children. Comparison of pre/post remediation measures indicated that it has promise as a technique for facilitating increased correct phoneme production.


Sign in / Sign up

Export Citation Format

Share Document