Loop Quantum Gravity. Starting from the generalization of the action function we have derived a theoretical background that leads to the quantization of gravity. The recent development of the loop approach has allowed us to explore domains ranging from black hole thermodynamics to the early Universe. This is what distinguishes quantum gravity from certain other unified field theories -- although, in fairness, some theories that are typically classified as quantum gravity … At the beginning of this new century, the problem of quantizing the gravitational field was still open. By then I'll have an adequate mathematical toolbox to study whatever has become of loop quantum gravity and/or string theory and thus be able to study them without reservation. Here's how this hangs together. Facing Quantum Gravity Theory". In LQG one begins with the assumptions that spacetime is quantum mechanical and that the theory is generally covariant and obeys the equivalence principle, then one finds that spacetime is quantised. What I and others have taken as most important about Ashtekar’s great
Feb 19, 2007 #4 Loop quantum gravity is the mathematical description of the quantum gravitational ﬁeld in terms of these loops.That is,the loops are quantum excitations of the Faraday lines of force of the gravitational ﬁeld.In low-energy approximations of the theory,these loops appear as gravitons – the fundamental particles that carry the gravitational force. The concept of ‘spin foam’ is intended to serve as a similar picture for the quantum geometry of spacetime. In general, a spin network is a graph with edges labelled by representations and vertices labelled by intertwining operators. Ships from and sold by Amazon.com. One of the great challenges facing physics today is to reconcile quantum theory and general relativity. Quantum gravity is an overall term for theories that attempt to unify gravity with the other fundamental forces of physics(which are already unified together). In this work, we propose a new approach to Quantum Gravity. loop quantum gravity is the most promising approach to quantum gravity. Quantum gravity is among the most fascinating problems in physics. It modifies our understanding of time, space and matter. Einstein's Loop quantum gravity is absolutely a quantum field theory, but it is not a local quantum field theory in the same sense as quantum electrodynamics (QED), for example. Loop quantum gravity is an approach to this challenge that incorporates quantum theory into our description of spacetime from the very start. Loop quantum gravity uses the formalism of spin-foams and generally covariant quantum mechanics (described in either of Carlo Rovelli’s known texts). It modifies our understanding of time, space and matter. This item: Covariant Loop Quantum Gravity: An Elementary Introduction to Quantum Gravity and Spinfoam Theory… by Carlo Rovelli Hardcover $68.63 Only 8 left in stock (more on the way).
“In loop quantum gravity we now have a clear picture of the quantum geometry of space, thanks in part to the theory of spin networks. Quantum versus everything else. Quantum gravity is among the most fascinating problems in physics. The recent development of the loop approach has allowed us to explore domains ranging from black hole thermodynamics to the early Universe. The two best theories we have, today, in physics – the Standard Model and General Relativity – are mutually incompatible; loop quantum gravity (LQG) is … It's a good thing I'm not a magician, and I can't keep secrets. This is not avoidence of hard problems, there are good physical reasons for this assertion, which I’d like to explain. It generally posits a theoretical entity, a graviton, which is a virtual particle that mediates the gravitational force.