Perturbation theory

Perturbation theory (quantum mechanics)

In quantum mechanics, perturbation theory is a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one. The idea is to start with a simple system for which a mathematical solution is known, and add an additional "perturbing" Hamiltonian representing a weak disturbance to the system. If the disturbance is not too large, the various physical quantities associated with the perturbed system (e.g. its energy levels and eigenstates) can be expressed as "corrections" to those of the simple system. These corrections, being small compared to the size of the quantities themselves, can be calculated using approximate methods such as asymptotic series. The complicated system can therefore be studied based on knowledge of the simpler one. In effect, it is describing a complicated unsolved system using a simple, solvable system. (Wikipedia).

Video thumbnail

OHM2013: Introduction to Quantum Perturbation

For more information visit: http://bit.ly/OHM13_web To download the video visit: http://bit.ly/OHM13_down Playlist OHM 2013: http://bit.ly/OHM13_pl Speaker: Karnei Gozman A birds eye view of the diagrammatic representation of Rayleigh-Schrödinger Perturbation Theory(RSPT), a general form

From playlist OHM 2013

Video thumbnail

The Theory that Solves "Unsolvable" Quantum Physics Problems - Perturbation Theory

Head over to https://www.Wondrium.com/ParthG to start your free trial today! Sometimes, certain problems in quantum mechanics become unsolvable due to their mathematical complexity. But we still have techniques for approximating their solutions! One such technique is perturbation theory -

From playlist Quantum Physics by Parth G

Video thumbnail

Feynman Diagrams and Perturbation Theory: Calculating in Particle Physics

In this video, we talk about how physicists perform calculations in particle physics using perturbation theory and Feynman diagrams. We discuss what perturbation theory is, how it relates to Feynman diagrams, how to read Feynman diagrams and how one actually gets a mathematical result out

From playlist Standard Model

Video thumbnail

Perturbation Theory in Quantum Mechanics - Cheat Sheet

In this video we present all the equations you need to know when you want to do time (in)dependent, (non-)degenerate perturbation theory in non-relativistic #QuantumMechanics References: [1] Sakurai, Napolitano, "Modern Quantum Mechanics". Table of Contents: 00:00 Introduction 00:57 T

From playlist Quantum Mechanics, Quantum Field Theory

Video thumbnail

Quantum Field Theory 4d - Second Quantization IV

We end our discussion of second quantization with the details of perturbation theory.

From playlist Quantum Field Theory

Video thumbnail

The 2n+1 Theorem | Perturbation Theory | Quantum Mechanics

In this video, we will explain the 2n+1 theorem and show you how to derive it. This theorem is useful when you want to calculate the energy of some system using perturbation theory, and has also found applications in density functional theory. References: [1] Baroni et al., "Phonons and

From playlist Quantum Mechanics, Quantum Field Theory

Video thumbnail

Advanced Quantum Physics Full Course | Quantum Mechanics Course

Quantum mechanics (QM; also known as #quantum #physics, quantum theory, the wave mechanical model, or #matrixmechanics), including quantum field theory, is a fundamental theory in physics which describes nature at the smallest scales of energy levels of atoms and subatomic particles. In t

From playlist Quantum Mechanics

Video thumbnail

Lecture 06 | Interactions I

In this lecture we introduce the basic ideas of perturbation theory for interacting theories: the S-matrix, interaction picture, and Fermi's golden rule. We use this to calculate our first physical observable in a toy model.

From playlist UC Davis: Brief Overview of Relativistic Quantum Field Theory

Video thumbnail

L9.4 Setting up perturbation theory

MIT 8.06 Quantum Physics III, Spring 2018 Instructor: Barton Zwiebach View the complete course: https://ocw.mit.edu/8-06S18 YouTube Playlist: https://www.youtube.com/playlist?list=PLUl4u3cNGP60Zcz8LnCDFI8RPqRhJbb4L L9.4 Setting up perturbation theory License: Creative Commons BY-NC-SA Mo

From playlist MIT 8.06 Quantum Physics III, Spring 2018

Video thumbnail

Semi-Classics, Adiabatic Continuity and Resurgence in Quantum Theories (Lecture 1) by Mithat Unsal

PROGRAM NONPERTURBATIVE AND NUMERICAL APPROACHES TO QUANTUM GRAVITY, STRING THEORY AND HOLOGRAPHY (HYBRID) ORGANIZERS: David Berenstein (University of California, Santa Barbara, USA), Simon Catterall (Syracuse University, USA), Masanori Hanada (University of Surrey, UK), Anosh Joseph (II

From playlist NUMSTRING 2022

Video thumbnail

Semi-Classics, Adiabatic Continuity and Resuregence in Quantum Theories (Lecture 2) by Mithat Unsal

PROGRAM NONPERTURBATIVE AND NUMERICAL APPROACHES TO QUANTUM GRAVITY, STRING THEORY AND HOLOGRAPHY (HYBRID) ORGANIZERS: David Berenstein (University of California, Santa Barbara, USA), Simon Catterall (Syracuse University, USA), Masanori Hanada (University of Surrey, UK), Anosh Joseph (II

From playlist NUMSTRING 2022

Video thumbnail

Quantum Geometry and Resurgent Perturbative/Non-perturbative Relations by Gerald Dunne

Nonperturbative and Numerical Approaches to Quantum Gravity, String Theory and Holography DATE:27 January 2018 to 03 February 2018 VENUE:Ramanujan Lecture Hall, ICTS Bangalore The program "Nonperturbative and Numerical Approaches to Quantum Gravity, String Theory and Holography" aims to

From playlist Nonperturbative and Numerical Approaches to Quantum Gravity, String Theory and Holography

Video thumbnail

Can We Observe the Quantum Origin of Primordial Perturbations? by Jerome Martin

PROGRAM: PHYSICS OF THE EARLY UNIVERSE - AN ONLINE PRECURSOR ORGANIZERS: Robert Brandenberger (McGill University, Montreal, Canada), Jerome Martin (Institut d'Astrophysique de Paris, France), Subodh Patil (Instituut-Lorentz for Theoretical Physics, Leiden, Netherlands) and L Sriramkumar (

From playlist Physics of The Early Universe - An Online Precursor

Video thumbnail

Introduction to Resurgence, Trans-series and Non-perturbative Physics II by Gerald Dunne

Nonperturbative and Numerical Approaches to Quantum Gravity, String Theory and Holography DATE:27 January 2018 to 03 February 2018 VENUE:Ramanujan Lecture Hall, ICTS Bangalore The program "Nonperturbative and Numerical Approaches to Quantum Gravity, String Theory and Holography" aims to

From playlist Nonperturbative and Numerical Approaches to Quantum Gravity, String Theory and Holography

Video thumbnail

Alexandre Tkatchenko - Many-body perturbation theory and wavefunction methods: A Physics perspective

Recorded 08 March 2022. Alexandre Tkatchenko of the University of Luxembourg presents "Many-body perturbation theory and wavefunction methods: A Physics perspective" at IPAM's Advancing Quantum Mechanics with Mathematics and Statistics Tutorials. Learn more online at: http://www.ipam.ucla.

From playlist Tutorials: Advancing Quantum Mechanics with Mathematics and Statistics - March 8-11, 2022

Video thumbnail

Dynamical Reduction in General Relativistic Contexts by Daniel Sudarsky

21 November 2016 to 10 December 2016 VENUE Ramanujan Lecture Hall, ICTS Bangalore Quantum Theory has passed all experimental tests, with impressive accuracy. It applies to light and matter from the smallest scales so far explored, up to the mesoscopic scale. It is also a necessary ingredie

From playlist Fundamental Problems of Quantum Physics

Video thumbnail

Alexandre Tkatchenko - Multiscale Approaches to Quantum Mechanics: Vacuum, Atoms, Engineering-Scale

Recorded 28 March 2022. Alexandre Tkatchenko of the University of Luxembourg presents "Multiscale Approaches to Quantum Mechanics: From Vacuum, to Atoms, to Engineering-Scale Structures" at IPAM's Multiscale Approaches in Quantum Mechanics Workshop. Learn more online at: http://www.ipam.uc

From playlist 2022 Multiscale Approaches in Quantum Mechanics Workshop

Video thumbnail

The Information Paradox and Holography by Suvrat Raju

ICTS at Ten ORGANIZERS: Rajesh Gopakumar and Spenta R. Wadia DATE: 04 January 2018 to 06 January 2018 VENUE: International Centre for Theoretical Sciences, Bengaluru This is the tenth year of ICTS-TIFR since it came into existence on 2nd August 2007. ICTS has now grown to have more tha

From playlist ICTS at Ten

Video thumbnail

Developments in superstring perturbation theory

Distinguished Visitor Lecture Series Developments in superstring perturbation theory Ashoke Sen Harish-Chandra Research Institute, Allahabad, India

From playlist Distinguished Visitors Lecture Series

Related pages

Covariant derivative | Schrödinger equation | Differential equation | Quantum harmonic oscillator | Nearly free electron model | Product rule | Hellmann–Feynman theorem | Chain rule | Coupling constant | Cooper pair | Connection (mathematics) | Particle in a box | Quark | Hydrogen atom | Hamiltonian (quantum mechanics) | Electron | Soliton | Density functional theory | Laplace transform | Fermi's golden rule | Power series | Taylor series | Vector bundle | Without loss of generality | Perturbation theory | Manifold | Divergent series | Complex number | Differential geometry | Variational method (quantum mechanics) | WKB approximation | Bra–ket notation | John William Strutt, 3rd Baron Rayleigh | Orthogonal complement