Join in expert discussion on quantum physics. Quantum physics is the mathematical description of the motion and interaction of subatomic particles. Quantum Mechanics and Field Theory.
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Undergrad Matrix element in problem with hydrogen atom
- Salmone
- · Replies 2 ·
Graduate Rigorous treatment of Grassmann numbers in fermionic path integrals
- taishizhiqiu
- · Replies 11 ·
Graduate Stern-Gerlach experiment: recombining spin-1/2 beams
- Christian Thom
- · Replies 15 ·
Undergrad How to find the wavefunction in this case?
- Kashmir
- · Replies 6 ·
Undergrad Degenerate perturbation theory: which linear combinations of states
- Kashmir
- · Replies 8 ·
Undergrad Classical analogy approach to quantum mechanics
- mohamed_a
- · Replies 21 ·
Undergrad Is it a fact that vacuum energy exists?
- Suekdccia
- · Replies 33 ·
Undergrad Particle on a sphere problem in quantum mechanics and its solution
- Kashmir
- · Replies 7 ·
Graduate Meaning of "symbol" in algebraic field theory?
- strangerep
- · Replies 5 ·
Undergrad Classical field in quantum field theory?
- Tan Tixuan
- · Replies 4 ·
Undergrad Uncertainty in an experiment with an image viewed through a big slit
- dom_quixote
- · Replies 3 ·
Graduate Could Altering the Past Be Possible with Time Travel?
- kb23455
- · Replies 1 ·
Undergrad Wavefunction in polar coordinates and its bra ket notation
- Kashmir
- · Replies 14 ·
Undergrad Operator acting on ket state n
- Jean-Mathys du bois
- · Replies 3 ·
Undergrad Effective mass in terms of electron states
- ergospherical
- · Replies 6 ·
Undergrad Time Dependent Sinusoidal Perturbation Energy Conservation
- Samama Fahim
- · Replies 7 ·
Graduate Schmidt decomposition - How do I find the matrix related to the state?
- Arquimedes
- · Replies 1 ·
Graduate Constructing the Wigner Function from Measurements of Entangled Photons
- neils
- · Replies 5 ·
Undergrad Position representation of product of operators in quantum mechanics
- Kashmir
- · Replies 18 ·
Undergrad Position representation of angular momentum operator
- Kashmir
- · Replies 10 ·
High School How Does Photon Polarization Influence Electron State Changes?
- msumm21
- · Replies 11 ·
Undergrad Applications of the proposed global quantum network of clocks
- phoenix-anna
- · Replies 8 ·
High School Quantum entanglement and energy conservation
- FR4S3R97
- · Replies 3 ·
Graduate Possible Ways to reduce Electron field Emission threshold
- domovinavi
- · Replies 1 ·
Undergrad Inner products with spherical harmonics in quantum mechanics
- Salmone
- · Replies 13 ·
Undergrad Schwartz derivation of the Feynman rules for scalar fields
- eoghan
- · Replies 1 ·
Graduate Does partial tracing make us see things that do not occur?
- Heidi
- · Replies 7 ·
Graduate Finding the Hermitian generator of a Symplectic transformation
- andresB
- · Replies 17 ·
Undergrad Ideas about observing position and momentum at the same time
- danielgossner
- · Replies 4 ·
Undergrad Is the moment of the measurement well defined?
- entropy1
- · Replies 12 ·
Undergrad Schrodinger equation for N particles in a box
- Kashmir
- · Replies 3 ·
Graduate What happens when you commute Sx and Sz in spin operators?
- Dennmac
- · Replies 2 ·
Undergrad Form of potential operator of two interacting particles
- Kashmir
- · Replies 3 ·
High School Higgs field and nuclear reactions
- Andrewtv848
- · Replies 7 ·
Undergrad Basic question on meaning of momentum operator
- Kashmir
- · Replies 56 ·
High School Special Relativity violation via Quantum Mechanics?
- thedubdude
- · Replies 12 ·
Undergrad What is the role of Relativistic QM?
- fxdung
- · Replies 40 ·
Graduate What do physicists mean when they say photons have a "path"?
- vanhees71
- · Replies 119 ·
High School Operator as the outcome of a measurement?
- Heidi
- · Replies 7 ·
Undergrad Propagation of uncertainty with some constants
- happyparticle
- · Replies 8 ·
Undergrad E=hf for massive particles, but which Energy exactly?
- AlonZ
- · Replies 5 ·
Undergrad Wavefunction of a free particle has carrier and envelope parts
- Kashmir
- · Replies 8 ·
Graduate Question while I study Modern Quantum physics by Sakurai
- BREAD
- · Replies 16 ·
Graduate Are Quantum Measurements Truly Special Cases of Unitary Operators?
- Heidi
- · Replies 1 ·
Undergrad Probability when measuring a local observable
- Yan Campo
- · Replies 1 ·
Undergrad Computing momentum expectation and variance for Gaussian wavefunction
- Kashmir
- · Replies 5 ·
Undergrad The probability density function for the double-slit experiment
- Ad VanderVen
- · Replies 19 ·
Undergrad Commutation relations for an interacting scalar field
- eoghan
- · Replies 3 ·
Undergrad Determination of entanglement by observing only one photon
- fluidfcs
- · Replies 20 ·
Graduate What is the Bell-like Inequality in Classical Physics?
- Heidi
- · Replies 6 ·
Graduate Is there a fixed relationship between momentum and position in the double-slit experiment?
- Ad VanderVen
- · Replies 4 ·
High School Virtual photons as force carriers
- ergo
- · Replies 29 ·
High School Does photon handedness change on reflection?
- Jeff Root
- · Replies 7 ·
Undergrad Difficulty in understanding step in Deriving WKB approximation
- curious_mind
- · Replies 6 ·
High School Why must light be described as particles instead of waves?
- Ray McDavis
- · Replies 12 ·
Undergrad What happens to photonic molecules?
- unsaint32
- · Replies 5 ·
Undergrad Multiple questions about eigenstates and eigenvalues
- Sebas4
- · Replies 3 ·
Graduate Generalized Forces and QED/QCD
- JohnH
- · Replies 14 ·
High School Multiple entanglements question
- brajesh
- · Replies 22 ·
Undergrad Collapse of wavefunction into a forbidden eigenstate for a free particle
- Kashmir
- · Replies 75 ·
Undergrad Wave function using the time dependent Schrodinger equation
- ThiagoSantos
- · Replies 1 ·
Graduate Noether and the derivative of the Action
- nemuritai
- · Replies 3 ·
Undergrad Irreducible solution of the harmonic oscillator with sin(ωt)
- George444fg
- · Replies 2 ·
Graduate What is the charge range for two N vacancies in a defect crystal?
- jackwangsg
- · Replies 1 ·
High School Special Relativity and the Measurement Problem of QM
- User2022
- · Replies 7 ·
High School Entangled particle decoherence question
- brajesh
- · Replies 4 ·
High School "Quantum Field Theory, as Simply as Possible" upcoming publication
- StevieTNZ
- · Replies 27 ·
Undergrad Is the Adjoint of the Position Operator Self-Adjoint?
- Kashmir
- · Replies 6 ·
Undergrad Infinite Square Well with an Oscillating Wall (Klein-Gordon Equation)
- Foracle
- · Replies 1 ·
Undergrad How to apply potential operator ##V(\hat{x})##
- Kashmir
- · Replies 2 ·
Undergrad Potential Energy of an Electron-Nuclei Interaction in DFT
- Dario56
- · Replies 1 ·
Graduate Double double slit experiment and path information
- Heidi
- · Replies 1 ·
High School What does it mean that a spin 1/2 particle needs two full rotations?
- vijayantv
- · Replies 6 ·
Undergrad Kinetic Energy and Potential Energy of Electrons
- Dario56
- · Replies 15 ·
Undergrad What is the physical meaning of concurence (quantum information)?
- Arquimedes
- · Replies 1 ·
Graduate Electron EM Field as Local Gauge Variation of Electron Matter Field
- CSnowden
- · Replies 6 ·
Undergrad How does projecting the Hamiltonian into position space give the Schrödinger equation?
- Kashmir
- · Replies 29 ·
Undergrad Probability current density of a stationary state
- Thomas Rigby
- · Replies 6 ·
High School Do particles spontaneously pair and merge in a vacuum?
- Quixotic Larry
- · Replies 4 ·
Undergrad Can Spinors Be Represented as Square Roots of Vectors in Clifford Algebra?
- Gerenuk
- · Replies 2 ·
Graduate Probabilities of couples of impacts - Bob and Alice and Young experiment
- Heidi
- · Replies 16 ·
Undergrad Can we accurately predict the properties of gold?
- bland
- · Replies 16 ·
Graduate QED Formulation with Massive Photon Fields
- M91
- · Replies 3 ·
Undergrad Can a Path Integral Formulation for Photons Start from a Massless Premise?
- gerald V
- · Replies 3 ·
Undergrad Odds of getting pairs -- QM version
- anuttarasammyak
- · Replies 1 ·
Undergrad Why Are There So Few Quantum Time Machine Models?
- avpol
- · Replies 13 ·
Undergrad Definition of magnetic moment in quantum mechanics
- Kashmir
- · Replies 6 ·
Undergrad Does it make sense to speak about the Grandfather paradox in QM?
- jordi
- · Replies 3 ·
Undergrad Hamiltonian of a particle in a magnetic field
- Kashmir
- · Replies 10 ·
Graduate Majorana representation of higher spin states
- fsh26
- · Replies 1 ·
Graduate Why Is Dissociation Rate Proportional to Current Raised to the Power of N?
- Piki
- · Replies 1 ·
Graduate Definition of finite size, radiative and weak magnetism corrections
- angweieng
- · Replies 3 ·
High School Does the Schrödinger Equation Imply a Deterministic Universe?
- Physics Slayer
- · Replies 4 ·
Graduate Entangled particles in curved spacetime
- Heidi
- · Replies 4 ·
Undergrad Exact dynamics of spin in varying magnetic field
- KDPhysics
- · Replies 1 ·
Graduate About Ruling Out Real-Valued Standard Formalism of Quantum Theory
- Haorong Wu
- · Replies 20 ·
Undergrad Quantum Mechanics without time?
- entropy1
- · Replies 9 ·
Undergrad Projection postulate and the state of a system
- Kashmir
- · Replies 9 ·
Undergrad Informational Interpretation of quantum mechanics?
- Mgt3
- · Replies 2 ·
Undergrad Spin, pseudo-spin or whatelse? (cavity)Polariton polarimetry question
- dchafatinos
- · Replies 4 ·