Quantum Physics Forum

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.

Threads

Graduate Question on spin-zero Feynman rules

  • Einj
  • · Replies 1 ·
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Graduate Has quantum physics proven that thoughts become reality?

  • Goosejournals
  • · Replies 6 ·
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Graduate Spontaneous symmetry breaking: How can the vacuum be infinitly degener

  • youngurlee
  • · Replies 4 ·
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Graduate Understanding Noether's Theorem in Quantum Field Theory - K. Huang's Explanation

  • jtceleron
  • · Replies 1 ·
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1

Graduate Where does the raised index come from in the Klein-Gordon equation?

  • spacelike
  • · Replies 3 ·
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Graduate Diffraction of individual photons

  • gespex
  • · Replies 5 ·
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5

Graduate Why don't scalar fields propagate superluminally?

  • ramparts
  • · Replies 2 ·
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2

Graduate What is the Quantum Force and How Does it Govern Atomic Vibrations?

  • somebody314
  • · Replies 14 ·
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Graduate Quantum mechanics without spacetime

  • math_04
  • · Replies 6 ·
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6

Graduate Discreet Quanta versus the Continuous Electromagnetic Spectrum

  • Mcellucci
  • · Replies 4 ·
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4

Graduate Are entangled particle outcomes determined by the unit circle?

  • rlduncan
  • · Replies 11 ·
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11

Graduate State space of QFT, CCR and quantization, and the spectrum of a field?

  • youngurlee
  • · Replies 1 ·
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Graduate Shrodinger's Waves, and Heisenberg's Matrices

  • Leucippus
  • · Replies 4 ·
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Graduate Why is ℏ under the square root in the momentum representation Fourier transform?

  • LagrangeEuler
  • · Replies 1 ·
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Graduate How Do You Compose Three Ket Vectors in Quantum Mechanics?

  • copernicus1
  • · Replies 7 ·
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Graduate Is there any evidence at all for quantum counscoiusness

  • batmanandjoker
  • · Replies 10 ·
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Graduate HUP and Conservation of momentum

  • g.lemaitre
  • · Replies 19 ·
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Undergrad Schrodinger equation dedution step?

  • tsuwal
  • · Replies 5 ·
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5

Graduate A physical example approximating the idealized situation

  • ENDLESSYOU
  • · Replies 1 ·
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Graduate Shadow on Wall: Light Blur from Wave or Quantum?

  • xzardaz
  • · Replies 2 ·
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Graduate What is the mathematical intuition behind operator embedding?

  • jshrager
  • · Replies 2 ·
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Graduate Bounding the speed of `spooky action at a distance'

  • thenewmans
  • · Replies 14 ·
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Graduate Why does the de Broglie wave function satisfy the Schrödinger equation?

  • Roodles01
  • · Replies 4 ·
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Graduate Bell State of two non-orthogonal modes

  • McLaren Rulez
  • · Replies 9 ·
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Graduate Scope of Pauli's Exclusion Principle

  • Aniket1
  • · Replies 3 ·
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Graduate Why Does Phase Velocity Differ in Relativistic and Non-Relativistic Cases?

  • qbslug
  • · Replies 1 ·
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Graduate Wave Particle Duality: Is It Mass-Energy Equivalence?

  • GeneralOJB
  • · Replies 1 ·
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Graduate Translation operator. Infinite potential well.

  • LagrangeEuler
  • · Replies 9 ·
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9

Graduate About spin being an internal symmetry

  • jtceleron
  • · Replies 2 ·
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Graduate Is spin the only physical parameter that can be entangled?

  • edpell
  • · Replies 3 ·
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Graduate Commuting Operators and Eigenfunctions in One Dimension

  • LagrangeEuler
  • · Replies 4 ·
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Graduate Relationship Between the Probability Current and Continuity Equation

  • darfmore
  • · Replies 1 ·
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Graduate What does orthogonality of quantum states mean physically?

  • pluspolaritons
  • · Replies 4 ·
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4

Graduate How to measure the external quantum efficiency of OLEDs?

  • Mr. Johnson
  • · Replies 4 ·
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4

Graduate Did weak measurements of photon polarization violate Heisenberg uncertainty?

  • Coin
  • · Replies 16 ·
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Graduate Uncertainty about Heisenberg Uncertainty Principle

  • Steve Brown
  • · Replies 22 ·
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Graduate Why do 4x4 quantum gates act on two-qubit systems?

  • pleasehelpmeno
  • · Replies 4 ·
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Graduate Can Negative Energy Be Produced in Small Amounts Through the Casimir Effect?

  • Chemist@
  • · Replies 9 ·
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Graduate About Schrödinger-Heisenberg connection

  • snoopies622
  • · Replies 5 ·
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Graduate The dirac equation of the hydrogen atom

  • Kamper
  • · Replies 5 ·
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Graduate Density matrix for bell states

  • pleasehelpmeno
  • · Replies 6 ·
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Graduate Does the Pauli exclusion principle emerge from fundamental quantum equations?

  • anorlunda
  • · Replies 7 ·
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Graduate Observables, Measurements and all that

  • spookyfw
  • · Replies 5 ·
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Graduate Lorentz contraction in the Quantum realm

  • fermi
  • · Replies 2 ·
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Graduate Hydrogen molecule in a small box, thought experiment

  • edpell
  • · Replies 3 ·
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3

Undergrad Why does higher frequency mean higher energy in photons?

  • petr1
  • · Replies 3 ·
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Graduate If the universe scaled down to the Planck length, would physics change?

  • DrZoidberg
  • · Replies 4 ·
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Graduate What affects the probability of finding a system in the ground state?

  • LagrangeEuler
  • · Replies 1 ·
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Graduate Could Quantum Entanglement Allow for Faster Than Light Communication?

  • Crazymechanic
  • · Replies 13 ·
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Graduate How can we measure the reality in quBits?

  • o0_manifold_0o
  • · Replies 4 ·
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Graduate On my way to Heisenberg uncert. princ.

  • 71GA
  • · Replies 1 ·
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Undergrad How Do Experimental Physicists Measure Momentum?

  • nonequilibrium
  • · Replies 24 ·
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Graduate Source of Virtual Particles in Space?

  • Ty1erC
  • · Replies 67 ·
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Graduate How is QED solved non-perturbatively, basic outline.

  • Spinnor
  • · Replies 7 ·
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Graduate QFT Ground State Analysis: Understanding e^(-iHT) |0>

  • silverwhale
  • · Replies 3 ·
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Graduate Photon into matter - antimatter pair production question.

  • esmeralda4
  • · Replies 1 ·
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Graduate Two questions on Clebsch-Gordan coefficients

  • Yoran91
  • · Replies 3 ·
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Graduate When to treat a particle as a wave based on de Broglie wavelength?

  • Hercuflea
  • · Replies 4 ·
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Graduate Breaking wavefunction into pieces

  • copernicus1
  • · Replies 1 ·
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Graduate Why Must Quantum Physics Involve Discrete Quanta?

  • TGlad
  • · Replies 9 ·
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9

Graduate Why don't virtual particles cause decoherence?

  • Mukilab
  • · Replies 131 ·
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Graduate I question the double-slit experiment:

  • Symmetry3
  • · Replies 4 ·
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Graduate Prove that the angular momentum operator is hermitian

  • Septim
  • · Replies 3 ·
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3

Graduate Pauli Exclusion Principle and Entanglement

  • g.lemaitre
  • · Replies 3 ·
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3

Graduate Why is Schrodinger's Cat entangled? Or is it not?

  • QuantumPixel
  • · Replies 3 ·
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3

Graduate Can Einstein-Rosen bridges exist and be traversed?

  • Kutt
  • · Replies 12 ·
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12

Graduate Understanding Quark-Gluon Vertex in QCD Feynman Rules

  • Einj
  • · Replies 7 ·
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7

Graduate Are |0⟩ and |1⟩ eigenvectors of σz by convention?

  • lewis198
  • · Replies 1 ·
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1

Graduate A little Bra-Ket notation theorem that I don't get

  • Excimer
  • · Replies 13 ·
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Graduate Free particle wave function and Ehrenfest's theorem

  • rays
  • · Replies 10 ·
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10

Graduate Spin orbit coupling and hydrogen problem

  • aaaa202
  • · Replies 1 ·
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Graduate Effect of photon detection mid-way between (double) slit and screen

  • San K
  • · Replies 2 ·
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2

Graduate Is Spin Networks Still Relevant in Quantum Gravity Research Today?

  • TGlad
  • · Replies 2 ·
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2

Graduate Why are Lz and Ly zero for an electron on a carbon nanotube surface?

  • aaaa202
  • · Replies 3 ·
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3

Graduate Time derivative of creation/annhilation operators

  • pleasehelpmeno
  • · Replies 3 ·
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3

Graduate Simultaneity of Uncertainty Principle

  • tomwilliam2
  • · Replies 3 ·
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3

Graduate Why are Bell's inequalities violated?

  • JK423
  • · Replies 97 ·
4
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Graduate Gaussian function to derive Heisenberg's uncertainty principle

  • 71GA
  • · Replies 19 ·
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Graduate Constructing a Toffoli gate with qubit gates?

  • randomafk
  • · Replies 1 ·
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1

Graduate Collapse of state vector for continuous eigenvalues

  • bob900
  • · Replies 3 ·
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3

Undergrad Paul Dirac's 1933 research paper

  • sudu.ghonge
  • · Replies 3 ·
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3

Graduate Proving Pauli Matrices are Generators of SU(2)

  • LayMuon
  • · Replies 11 ·
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11

Graduate Will an electron vibrating in a 1D radiates?

  • thitchen
  • · Replies 7 ·
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7

Graduate Understanding Spin Orbit Coupling: Deriving the Hamiltonian

  • aaaa202
  • · Replies 1 ·
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1

Graduate About interchange phase of identical particles in Weinberg's QFT book

  • kof9595995
  • · Replies 5 ·
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5

Graduate Why does high particle momentum imply short-scale physics in the uncertainty principle?

  • ndung200790
  • · Replies 8 ·
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8

Graduate I don't understand why -1/2 is the higher energy level and +1/2 is the

  • duggielanger
  • · Replies 1 ·
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1

Graduate Group velocity in infinite square well

  • 8Apeiron8
  • · Replies 3 ·
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3

Undergrad Black body and continuous spectrum

  • jaumzaum
  • · Replies 3 ·
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3

Graduate I am getting into a mess with the HUP

  • MHD93
  • · Replies 12 ·
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12

Graduate A question on the product of two real linear operators

  • Excimer
  • · Replies 2 ·
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2

Undergrad The heck with the Cat, what about the Human?

  • jmoorhea
  • · Replies 8 ·
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8

Graduate What is the state vector after measuring

  • aaaa202
  • · Replies 7 ·
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7

Graduate Why is the exponential derivative operator a translational operator?

  • matematikuvol
  • · Replies 10 ·
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10

Graduate What is a pure quantum state and a mixed quantum state?

  • rsaad
  • · Replies 4 ·
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4

Graduate Maxwell's equations from U(1) symmetry

  • Thoros
  • · Replies 5 ·
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5

Graduate Is radioactive decay reversible in time?

  • Izzhov
  • · Replies 2 ·
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Graduate Quantum Communication: Two-Way Messaging Without Physical Link?

  • Stanley514
  • · Replies 3 ·
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3

Graduate Is the Book's Photon Calculation Off by a Factor of 1000?

  • Fluxthroughme
  • · Replies 5 ·
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5

Graduate Heisenberg's uncertainty principle invalidated?

  • quantumphilosopher
  • · Replies 23 ·
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23