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 Quantum Immortality: Implications of MWI on Death?

  • blah_blah
  • · Replies 6 ·
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Graduate Symmetry factors in Feyman Diagrams

  • vertices
  • · Replies 7 ·
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7

Graduate Local density of number of photons

  • paweld
  • · Replies 1 ·
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Graduate Sommerfeld quantisation:relation between energy and potential

  • krishna mohan
  • · Replies 2 ·
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2

Graduate S-orbitals, angular momentum and Heisenberg uncertainty

  • Scraping Rust
  • · Replies 5 ·
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5

Graduate How can I solve for Equation 2.16 in Srednicki?

  • LAHLH
  • · Replies 3 ·
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3

Graduate Simplifying Feynman Diagram for Nasty 10 Point Green's Function?

  • vertices
  • · Replies 1 ·
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Graduate The expectation of an expection (relating to Wick's Theorem)

  • vertices
  • · Replies 4 ·
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4

Graduate Understanding Normalization in Spin Sum: Peskin vs. Kaku and Zee's Approach"

  • nklohit
  • · Replies 1 ·
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Graduate Photon absorption via changing EM field

  • Edi
  • · Replies 1 ·
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Graduate Weight of electrons and positrons after they annihilate into gamma rays

  • Raekwon
  • · Replies 13 ·
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Graduate S-Matrix in non-relativistic limit

  • nklohit
  • · Replies 2 ·
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Graduate How Do We Calculate the Composite Spin of a System with Three or More Particles?

  • Xian
  • · Replies 3 ·
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Graduate Why quantum entanglement differs from separating red and blue pens

  • tell_me_why
  • · Replies 4 ·
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4

Graduate Is there an equivalent of the HUP for spins?

  • nomadreid
  • · Replies 19 ·
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19

Graduate Electrodynamics question and maybe quantum/classical misunderstanding

  • jfy4
  • · Replies 4 ·
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4

Undergrad Does a laser experience recoil due to photon momentum?

  • ssope
  • · Replies 46 ·
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Undergrad How is it then when you colide 2 protons

  • clm321
  • · Replies 19 ·
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19

Graduate Integral involving exponentials and the Time ordering operator

  • vertices
  • · Replies 4 ·
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4

Undergrad Quantization of Length: Can You Achieve Every Length Between 1" and 2"?

  • Axuality
  • · Replies 7 ·
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Graduate Is there a quantum mechanical acceleration operator?

  • jfy4
  • · Replies 9 ·
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9

Graduate Understanding Spin: Share Your Ideas!

  • luxiaolei
  • · Replies 5 ·
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5

Graduate Perturbation Theory: Deciphering Missing Lines of Explanation

  • vertices
  • · Replies 5 ·
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Graduate Solving radial wavefunction in odd central potential

  • FunkyDwarf
  • · Replies 2 ·
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Graduate Understanding S-Wave and P-Wave Annihilation

  • fliptomato
  • · Replies 4 ·
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Graduate Bound states of Yukawa potential

  • drummerguy
  • · Replies 1 ·
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Graduate Energy Uncertainty Less For High-Energy Particles?

  • LarryS
  • · Replies 2 ·
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Graduate Does instantaneous communication implies a preferrred Lorentz frame?

  • Demystifier
  • · Replies 137 ·
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Graduate What is semi-classical level counting?

  • jostpuur
  • · Replies 5 ·
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5

Graduate What Are the Implications of Srednicki's \langle 0 \mid \phi(x) \mid 0 \rangle?

  • LAHLH
  • · Replies 2 ·
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Graduate Why use complex exponentials for matter waves instead of sines

  • zodas
  • · Replies 7 ·
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7

Undergrad How does quantum observation affect particles without physical contact?

  • GUS
  • · Replies 5 ·
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5

Graduate Representations and change of basis

  • Niles
  • · Replies 1 ·
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Graduate Behaviour of electron as wave and Particle

  • KK
  • · Replies 25 ·
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25

Graduate Computing cellular homology with Macaulay2

  • Chris Hillman
  • · Replies 8 ·
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8

Graduate Are Shankar's equations for example 1.8.6 wrong?

  • juan123
  • · Replies 1 ·
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Graduate Oscillation frequency of probability density P(x,t)

  • nhk150709
  • · Replies 2 ·
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Graduate Hydrogen spin-orbit interaction

  • ian2012
  • · Replies 6 ·
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6

Undergrad How gravity can be bent if its just a messender particle.

  • clm321
  • · Replies 8 ·
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8

Graduate Lorentz Invariant Majorana Neutrinos

  • rkrsnan
  • · Replies 8 ·
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Graduate Writing a matrix as an outer product expansion.

  • raisin_raisin
  • · Replies 9 ·
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Graduate Solution for Dirac equation with zero mass.

  • rkrsnan
  • · Replies 4 ·
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4

Graduate Orthochronous Lorentz Transformations

  • vertices
  • · Replies 1 ·
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Graduate Showing that commutator is invariant under orthchronous LTs

  • vertices
  • · Replies 5 ·
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Graduate Entanglement and Concurrence: asking for definitions

  • DaTario
  • · Replies 3 ·
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Graduate Reflection coefficient for finite square barrier scattering

  • ronaldoshaky
  • · Replies 5 ·
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Graduate Why is wavefunction complex-valued?

  • cadamcross2
  • · Replies 8 ·
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Graduate Probabilistics of Quantum Physics

  • Svensken
  • · Replies 5 ·
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5

Graduate Psi-Collapse in Nature: Definition and Implications

  • The thinker
  • · Replies 1 ·
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Undergrad Does Hawking radiation make smaller black holes decay faster?

  • srfriggen
  • · Replies 4 ·
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Graduate Is My Normalized Wave Function Accurate?

  • intervoxel
  • · Replies 5 ·
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Graduate Feynman propagator on the cylinder - position space representation

  • DrFaustus
  • · Replies 7 ·
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Graduate Understanding Lowering Operator A and Hermitianity

  • ronaldoshaky
  • · Replies 1 ·
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Graduate Quantum Tunneling math and Schrodinger's Equation

  • Stevenpd
  • · Replies 1 ·
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Graduate Free particles in second quantization

  • Niles
  • · Replies 11 ·
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Graduate BRS: euclidean surfaces a la Cartan

  • Chris Hillman
  • · Replies 3 ·
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3

Graduate Matrix Transformation: U^\dagger vs U

  • Niles
  • · Replies 3 ·
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Graduate Uncertainty principle consist with energy conservation?

  • luxiaolei
  • · Replies 11 ·
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11

Graduate Tensor product of vector spaces: confusion

  • Goldbeetle
  • · Replies 4 ·
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4

Graduate Is superposition describing all potential states of a particle?

  • MattAndMatthe
  • · Replies 4 ·
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4

Graduate Energy Principle and Hydrogen Atom

  • sharma_satdev
  • · Replies 9 ·
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9

Graduate Dirac equation for many particles system

  • ranytawfik
  • · Replies 8 ·
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Graduate Rectangular Potential well if hbar -> 0

  • divB
  • · Replies 5 ·
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Graduate Error in book? (derivation of quantum well)

  • divB
  • · Replies 2 ·
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2

Graduate Equation for quantizing general relativity from Seeing Black Holes

  • kazparov
  • · Replies 6 ·
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6

Graduate Does the Chain Rule Apply to Gauge Transformations in Lie Groups?

  • vertices
  • · Replies 3 ·
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Graduate Uncertainty principle on P and E exchange

  • luxiaolei
  • · Replies 10 ·
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Graduate Heuristic derivation of Schrodinger's equation for a layman

  • jdstokes
  • · Replies 15 ·
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Graduate Probability Density of Particle in Potential Well

  • ronaldoshaky
  • · Replies 1 ·
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Graduate Gravitational force on observed particle?

  • Xenoman
  • · Replies 4 ·
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4

High School What Are Will 'O The Wisp and Foo Fighters?

  • Leah
  • · Replies 53 ·
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High School If light is a wave then how can it be formed into a laser?

  • chopficaro
  • · Replies 12 ·
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12

Graduate Vacuum fluctuations and matter

  • GeorgCantor
  • · Replies 14 ·
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14

Graduate Differential Geometry and Quantum Mechanics

  • Reedeegi
  • · Replies 3 ·
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3

Graduate Notation relating to gamma matrices

  • vertices
  • · Replies 9 ·
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9

Graduate Lippmann-Schwinger Equation

  • <bra|ket>
  • · Replies 1 ·
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1

Graduate What Are the Degrees of Freedom in Lorenz and Columb Gauges?

  • mkbh_10
  • · Replies 1 ·
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1

Graduate Degeneracy and Symmetrization Requirement

  • hbweb500
  • · Replies 6 ·
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6

Undergrad What is Schrödinger's cat used to explain?

  • wuko
  • · Replies 5 ·
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5

Graduate Antisymmetric wavefunctions for more than two particles

  • quasar_4
  • · Replies 1 ·
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1

Graduate Double-Slit Experiment vs Identical Particles

  • LarryS
  • · Replies 3 ·
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3

Graduate Why Did My Teacher Make a Substitution in Transforming a Hamiltonian?

  • Niles
  • · Replies 5 ·
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5

Graduate Raising and Lowering Indices and expansion

  • vertices
  • · Replies 6 ·
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6

Graduate Why Don't Photons Get Absorbed in Double Slit Experiments?

  • alex440
  • · Replies 2 ·
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2

Undergrad Einstein's theory on photoelectric effect

  • agtee
  • · Replies 6 ·
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6

Undergrad Compton vs Photoelectric effect?

  • pivoxa15
  • · Replies 12 ·
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12

Graduate Adding spin components on different axes x+x=Z?

  • chopficaro
  • · Replies 3 ·
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3

Graduate Why is quantum spacetime necessarily random?

  • flufffrost
  • · Replies 4 ·
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4

Graduate Probablity density of 1s in hydrogen atom

  • Karrar
  • · Replies 1 ·
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1

Graduate Finding \Psi(x,t) From Schrodinger Equation

  • puneet.988
  • · Replies 5 ·
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5

Graduate What if Hamiltonian is not constant in time?

  • jostpuur
  • · Replies 10 ·
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10

Graduate Can Photon Energy Be Equated to Kinetic and Potential Energy?

  • manifested
  • · Replies 3 ·
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3
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3

Graduate Srednicki QFT chapter 8 question

  • LAHLH
  • · Replies 3 ·
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3

Graduate Is quantum potentiality more like weight or a wave?

  • MattAndMatthe
  • · Replies 2 ·
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2

Graduate Is energy of a free particle observable?

  • sweet springs
  • · Replies 40 ·
2
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40

Undergrad What vibrates in De Broglie waves?

  • shripathee
  • · Replies 6 ·
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6

Graduate How do gauge transformations relate to constraints in canonical quantization?

  • mtak0114
  • · Replies 8 ·
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8

Graduate Photon Off a Mirror: How Does It Work?

  • cragar
  • · Replies 4 ·
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4

Graduate Solving the Schrödinger Equation for a Step Potential

  • laharl88
  • · Replies 10 ·
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10