History of gravitational theory
In physics, theories of gravitation postulate mechanisms of interaction governing the movements of bodies with mass. There have been numerous theories of gravitation since ancient times.
In the 4...
A New ‘Einstein’ Equation Suggests Wormholes Hold Key To Quantum Gravity
A new Einsteinian equation, ER=EPR, may be the clue physicists need to merge quantum mechanics with general relativity.
Much Like White Light, Spacetime Is Also Composed Of A Certain Rainbow
When white light is passed through a prism, the rainbow on the other side reveals a rich palette of colors. Theorists from the Faculty of Physics, University of Warsaw have shown that in models of th...
What Happens If You Fall Into A Black Hole?
Quanta Magazine’s new In Theory video series, featuring David Kaplan, a theoretical particle physicist at Johns Hopkins University and the producer of the award-winning documentary Particle Fever, pro...
Opening a window on quantum gravity
Yale University has received a grant from the W. M. Keck Foundation to fund experiments that researchers hope will provide new insights into quantum gravity. Jack Harris, associate professor of physic...
Aristotelian physics
Aristotelian physics is a form of natural science described in the works of the Greek philosopher Aristotle (384–322 BCE). In the Physics, Aristotle established general principles of change that ...
Aristotelian physics - Wikipedia
Law of universal gravitation
Professor Walter Lewin explains Newton's law of gravitation during the 1999 MIT Physics course 8.01 Newton's law of universal gravitation states that any two bodies in the universe attract eac...
Law of universal gravitation - Wikipedia
Mechanical explanations of gravitation
Mechanical explanations of gravitation (or kinetic theories of gravitation) are attempts to explain the action of gravity by aid of basic mechanical processes, such as pressure forces caused by pushes...
Mechanical explanations of gravitation - Wikipedia
Introduction to general relativity
General relativity is a theory of gravitation that was developed by Albert Einstein between 1907 and 1915. According to general relativity, the observed gravitational effect between masses results fro...
Introduction to general relativity - Wikipedia
Graviton
In physics, the graviton is a hypothetical elementary particle that mediates the force of gravitation in the framework of quantum field theory. If it exists, the graviton is expected to be massless (b...
Quantum gravity
Quantum gravity (QG) is a field of theoretical physics that seeks to describe the force of gravity according to the principles of quantum mechanics.The current understanding of gravity is based on Alb...
Quantum gravity - Wikipedia
Quantum gravity epoch
In physical cosmology, the Planck epoch (or Planck era) is the earliest period of time in the history of the universe, from zero to approximately 10 seconds (Planck time). It is believed that, due to ...
Diffeomorphism constraint
In theoretical physics, it is often important to study theories with the diffeomorphism symmetry such as general relativity. These theories are invariant under arbitrary coordinate transformations. Eq...
Causal sets
The causal sets programme is an approach to quantum gravity. Its founding principle is that spacetime is fundamentally discrete and that the spacetime events are related by a partial order. This parti...
Causal sets - Wikipedia
AdS/CFT correspondence
In theoretical physics, the anti-de Sitter/conformal field theory correspondence, sometimes called Maldacena duality or gauge/gravity duality, is a conjectured relationship between two kinds of physic...
AdS/CFT correspondence - Wikipedia
Amplituhedron
An amplituhedron is a geometric structure that enables simplified calculation of particle interactions in some quantum field theories. In planar N = 4 supersymmetric Yang–Mills theory, an amplituhedro...
IR/UV mixing
In theoretical physics, it is usually possible to organize physical phenomena according to the energy scale or distance scale. The theory of renormalization group is based on this paradigm. The short-...
Immirzi parameter
The Immirzi parameter (also known as the Barbero-Immirzi parameter) is a numerical coefficient appearing in loop quantum gravity, a nonperturbative theory of quantum gravity. The Immirzi parameter mea...
Composite gravity
In theoretical physics, composite gravity refers to models that attempted to derive general relativity in a framework where the graviton is constructed as a composite bound state of more elementary pa...
List of loop quantum gravity researchers
This is a partial list of notable researchers in the physics field of loop quantum gravity.
List of loop quantum gravity researchers - Wikipedia
Group field theory
Group field theory (GFT) is a quantum field theory in which the base manifold is taken to be a Lie group. It is closely related to background independent quantum gravity approaches such as loop quantu...
Kodama state
In 1988, Hideo Kodama wrote down the equations of the Kodama state, but as it described a positive (de Sitter universe) spacetime, which was believed to be inconsistent with observation, it was largel...
Spin foam
In physics, a spinfoam or spin foam is a topological structure made out of two-dimensional faces that represents one of the configurations that must be summed to obtain a Feynman's path integral (fun...
Renormalization
In quantum field theory, the statistical mechanics of fields, and the theory of self-similar geometric structures, renormalization is any of a collection of techniques used to treat infinities arising...
Renormalization - Wikipedia
Loop quantum cosmology
Loop quantum cosmology (LQC) is a finite, symmetry-reduced model of loop quantum gravity (LQG) that predicts a "quantum bridge" between contracting and expanding cosmological branches.The distinguishi...
Quantum geometry
In theoretical physics, quantum geometry is the set of new mathematical concepts generalizing the concepts of geometry whose understanding is necessary to describe the physical phenomena at very short...
Quantum foam
Quantum foam (also referred to as space-time foam) is a concept in quantum mechanics devised by John Wheeler in 1955. The foam is supposed to be conceptualized as the foundation of the fabric of the u...
Ashtekar variables
In the ADM formulation of General relativity one splits spacetime into spatial slices and time, the basic variables are taken to be the induced metric, , on the spatial slice (the metric induced on th...
Euclidean quantum gravity

In physics, a Wick rotation, named after Gian-Carlo Wick, is a method of finding a solution to dynamics problems in n dimensions, by transposing their descriptions in n+1 dimensions, by trading o...
Canonical quantum gravity
In physics, canonical quantum gravity is an attempt to quantize the canonical formulation of general relativity (or canonical gravity). It is a Hamiltonian formulation of Einstein's general theory of ...