Does quantum gravity exist?

A Quantum Field Theory of gravity does not exist, because it is not possible to quantize a background-independent theory of spacetime by means of a background-dependent approach, describing a dynamics on (an already fixed) spacetime. It is not possible to describe the quantum dynamics of spacetime on spacetime.

Does quantum mechanics explain gravity?

Quantum mechanics suggests everything is made of quanta, or packets of energy, that can behave like both a particle and a wave—for instance, quanta of light are called photons. Detecting gravitons, the hypothetical quanta of gravity, would prove gravity is quantum. The problem is that gravity is extraordinarily weak.

Do gravitons contradict general relativity?

No, gravitons are not incompatible with GR. The same way gravity is the manifestation of the curvature of the space-time metric tensor, the other three fundamental forces are defined as the curvature of their own respective gauge fields.

Is loop quantum gravity true?

Loop quantum gravity (LQG) is a theory of quantum gravity, which aims to merge quantum mechanics and general relativity, incorporating matter of the Standard Model into the framework established for the pure quantum gravity case. Consequently, not just matter, but space itself, prefers an atomic structure.

Has the graviton been discovered?

Unfortunately, the two don’t mesh very well. One consequence of that: while scientists know of particles associated with the strong, weak and electromagnetic forces, they have yet to discover a particle of gravity, or graviton.

Are gravitons proven?

As Fermilab senior physicist Don Lincoln wrote in a post: “Gravitons are a theoretically reputable idea, but are not proven. So if you hear someone say that ‘gravitons are particles that generate the gravitational force,’ keep in mind that this is a reasonable statement, but by no means is it universally accepted.

Are there anti gravitons?

Gravitons were discovered and Gravitons operate on mass, and mass comes in only in positive amounts. Antigravitons do not exist (source 2). Physicists are searching for the particle responsible for the gravitational force.

What is semiclassical gravity?

Semiclassical gravity. Semiclassical gravity is the approximation to the theory of quantum gravity in which one treats matter fields as being quantum and the gravitational field as being classical.

Is semiclassical gravity possible from an axiomatic approach?

Semiclassical gravity can also be deduced from an axiomatic approach. There are cases where semiclassical gravity breaks down. For instance, if M is a huge mass, then the superposition

What are the different types of gravity?

Gravity: from Classical, Semi-Classical, Stochastic to Quantum 林世昀Shih-Yuin Lin National Center for Theoretical Sciences June 1, 2007 @ NTHU Outline I. Classical Gravity II. Semiclassical Gravity III. Stochastic to Quantum Gravity IV. Concluding Remarks Prologue „Theoretical Science: logical explanation, falsifiable prediction

What is the theory of singularity of gravity?

I. Classical Gravity „Singularity Theorem (Penrose, Hawking, Geroch, 1960s) – Gravitation is always attractive (~ energy conditions) If there is a trapped null surface and the energy density is nonnegative, then there exist geodesic of finite length which can’t be extended.