Riemannian manifolds | 4-manifolds
In mathematical physics and differential geometry, a gravitational instanton is a four-dimensional complete Riemannian manifold satisfying the vacuum Einstein equations. They are so named because they are analogues in quantum theories of gravity of instantons in Yang–Mills theory. In accordance with this analogy with self-dual Yang–Mills instantons, gravitational instantons are usually assumed to look like four dimensional Euclidean space at large distances, and to have a self-dual Riemann tensor. Mathematically, this means that they are asymptotically locally Euclidean (or perhaps asymptotically locally flat) hyperkähler 4-manifolds, and in this sense, they are special examples of Einstein manifolds. From a physical point of view, a gravitational instanton is a non-singular solution of the vacuum Einstein equations with positive-definite, as opposed to Lorentzian, metric. There are many possible generalizations of the original conception of a gravitational instanton: for example one can allow gravitational instantons to have a nonzero cosmological constant or a Riemann tensor which is not self-dual. One can also relax the boundary condition that the metric is asymptotically Euclidean. There are many methods for constructing gravitational instantons, including the Gibbons–Hawking Ansatz, twistor theory, and the hyperkähler quotient construction. (Wikipedia).
Minute Physics: What is Gravity?
One Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in one minute! In this episode, we discuss the basic nature of gravity, one of the four fundamental forces in our universe. Come back for a new video every week! Created by Henry
From playlist Gravity
Gravitational Field Introduction
The gravitational field is introduced and illustrated. For a constant field and a non-constant field around a spherical object. Want Lecture Notes? http://www.flippingphysics.com/gravitational-field.html This is an AP Physics 1 topic. 0:00 The two force of gravity equations 0:55 The const
From playlist IB Physics 6.2: Newton's Law of Gravitation
Teach Astronomy - Universal Law of Gravity
http://www.teachastronomy.com/ Newton's master work is the universal law of gravity. Newton's law of gravity states that every object in the universe, every particle, every planet, every star, every galaxy, attracts each other with a force that is proportional to each of the masses of two
From playlist 03. Concepts and History of Astronomy and Physics
When massive objects crash into each other, there should be a release of gravitational waves. So what are these things and how can we detect them? Support us at: http://www.patreon.com/universetoday More stories at: http://www.universetoday.com/ Follow us on Twitter: @universetoday Follow
From playlist Gravity
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From playlist Science Unplugged: General Relativity
Prim Plansangkate: Skyrme fields, multi-instantons and the SU(∞)-Toda equation
We construct Skyrme fields from holonomy of the spin connection of multi-Taub-NUT instantons with the centres positioned along a line in R3. The domain of our Skyrme fields is the space of orbits of the axial symmetry of the multi-Taub-NUT instantons. We obtain an expression for the induc
From playlist Mathematical Physics
Gravitation (4 of 17) Calculating Acceleration Due to Gravity (g)
Shows how to calculate the acceleration due to gravity. The equation is derived from Newton's second law and Newton's Law of universal gravitation. The acceleration due to gravity is the acceleration on an object caused by the force of gravitation. All bodies accelerate in a gravitati
From playlist Gravitation: Orbital Velocity, Orbital Period, Potential Energy, Kinetic Energy, Mass and Weight
Instantons and Monopoles (Lecture 1) by Sergey Cherkis
Program: Quantum Fields, Geometry and Representation Theory ORGANIZERS : Aswin Balasubramanian, Saurav Bhaumik, Indranil Biswas, Abhijit Gadde, Rajesh Gopakumar and Mahan Mj DATE & TIME : 16 July 2018 to 27 July 2018 VENUE : Madhava Lecture Hall, ICTS, Bangalore The power of symmetries
From playlist Quantum Fields, Geometry and Representation Theory
Antonio Marcianò : Kac-Moody instantons in space-time forma as an alternative solution to the ...
Recording during the thematic meeting : "Geometrical and Topological Structures of Information" the August 31, 2017 at the Centre International de Rencontres Mathématiques (Marseille, France) Filmmaker: Guillaume Hennenfent
From playlist Geometry
Physics - Mechanics: Gravity (1 of 20) Newton's Law of Gravity
Visit http://ilectureonline.com for more math and science lectures! In this video I will explain Newton's Law of Gravity and give an example of how it works.
From playlist PHYSICS 18 GRAVITY
Topological Susceptibility and the Sphaleron Rate in QCD and the Electroweak Theory by Guy Moore
DISCUSSION MEETING TOPOLOGICAL ASPECTS OF STRONG CORRELATIONS AND GAUGE THEORIES (ONLINE) ORGANIZERS: Rob Pisarski (Brookhaven National Laboratory, USA), Sumathi Rao (HRI, India), Soeren Schlichting (Bielefeld University, Germany) and Sayantan Sharma (IMSc, India) DATE: 06 September 202
From playlist Topological aspects of strong correlations and gauge theories (ONLINE)
Universal Gravitational Potential Energy Introduction
Universal Gravitational Potential Energy is introduced and graphed. It is compared to the force of gravity. And the “zero line” is defined. Want Lecture Notes? http://www.flippingphysics.com/universal-gravitational-potential-energy.html This is an AP Physics 1 topic. 0:00 Intro 0:11 “Norm
From playlist Gravity - A Level Physics
Quantum gravity constraints on large-field inflation - L. McAllister - Workshop 1 - CEB T3 2018
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From playlist 2018 - T3 - Analytics, Inference, and Computation in Cosmology
Michael Green -- String Scattering Amplitudes, Feynman diagrams, and M-theory
This workshop seeks to explore connections between geometric flows and other areas of mathematics and physics. Geometric flows refer to ways in which geometry can be deformed smoothly in time, rather analogous to the way in which the geometry of the surface of a balloon becomes smooth and
From playlist Research Lectures
An Oxford Mathematics Graduate Supervision - Geometry and Physics in 7 Dimensions
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From playlist Oxford Mathematics Student Tutorials and Graduate Supervisions
Gravitation (10 of 17) Gravitational PE at the Surface of the Earth
Explains how to calculate the gravitational potential energy of an object at the surface of the Earth. Gravitational potential energy is the energy associated with a gravitational field. Gravitational energy is dependent on the masses of the two objects, the distance between them and the g
From playlist Gravitation: Orbital Velocity, Orbital Period, Potential Energy, Kinetic Energy, Mass and Weight
Higher Topological Charge Effects in QCD and Beyond by Fabian Rennecke
DISCUSSION MEETING TOPOLOGICAL ASPECTS OF STRONG CORRELATIONS AND GAUGE THEORIES (ONLINE) ORGANIZERS: Rob Pisarski (Brookhaven National Laboratory, USA), Sumathi Rao (HRI, India), Soeren Schlichting (Bielefeld University, Germany) and Sayantan Sharma (IMSc, India) DATE: 06 September 202
From playlist Topological aspects of strong correlations and gauge theories (ONLINE)
What is Gravity? | Physics | Gravitation | Don't Memorise
Do we really know what Gravity means? What is Gravity? What are the questions we should ask regarding the concept of Gravity? Watch this video to know more! To learn more about Gravitation, enroll in our full course now: https://infinitylearn.com/microcourses?utm_source=youtube&utm_mediu
From playlist Physics