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 Remind me where to find a proof of a spectral theorem for RHS

  • Fredrik
  • · Replies 4 ·
Replies
4

Graduate If you measure the energy of a system how does wave function collapse

  • cooev769
  • · Replies 12 ·
Replies
12

Graduate Is There Experimental Proof of Photon Existence Beyond Emission and Absorption?

  • JCMaxwell
  • · Replies 3 ·
Replies
3

Graduate Why is there little decoherence for photons?

  • Halaaku
  • · Replies 10 ·
Replies
10

Graduate How to compute Von Neumann entropy?

  • naima
  • · Replies 7 ·
Replies
7

Graduate Virtual particles and the Uncertainity Principle

  • Yashbhatt
  • · Replies 6 ·
Replies
6

Graduate Shape of the magnet in the Stern-Gerlach experiment

  • carllacan
  • · Replies 1 ·
Replies
1

Graduate Set Up Eigenspace for Particle in 1st State: nx,ny,nz

  • helpppmeee
  • · Replies 7 ·
Replies
7

Graduate Understanding Coupled Spin Operators

  • cooev769
  • · Replies 7 ·
Replies
7

Graduate Net Angular Momentum: Clarifying Confusion

  • cooev769
  • · Replies 3 ·
Replies
3

Graduate Understanding S-matrix elements in QFT

  • "Don't panic!"
  • · Replies 6 ·
Replies
6

Graduate How Do Matrix Representations Relate to Wave Functions in Quantum Mechanics?

  • cooev769
  • · Replies 3 ·
Replies
3

Graduate Photon's change of direction of propagation

  • Goodver
  • · Replies 1 ·
Replies
1

Graduate Is it possible to do quantum mechanics without complex functions

  • cooev769
  • · Replies 12 ·
Replies
12

Graduate Is there a law which prohibits measuring En of a non-stationary state

  • cooev769
  • · Replies 6 ·
Replies
6

Graduate Adiabatic switching vs wavepackets for deriving the S-matrix

  • geoduck
  • · Replies 10 ·
Replies
10

Graduate Numerical solution of one dimensional Schrodinger equation

  • mojtaba m
  • · Replies 3 ·
Replies
3

Undergrad Molecular orbitals sigma and pi

  • pamelmf
  • · Replies 3 ·
Replies
3

Graduate Is Negative Mass Possible in String Theory Through Quantum Fluctuations?

  • Strange_matter
  • · Replies 1 ·
Replies
1

Graduate What is the wave equation for the Casimir Effect and how was it derived?

  • epislon58
  • · Replies 1 ·
Replies
1

Graduate Kinetic Energy of particle in 1D and 3D well

  • PsychonautQQ
  • · Replies 2 ·
Replies
2

Graduate Retro causation in weak measurements?

  • Murgue
  • · Replies 1 ·
Replies
1

Graduate Questions about quantum fields

  • AtomicCanadian
  • · Replies 5 ·
Replies
5

Graduate A Negation of the Grandfather Paradox

  • jacirez
  • · Replies 3 ·
Replies
3

Graduate Differential of exponential operator

  • SK1.618
  • · Replies 2 ·
Replies
2

Undergrad Can someone explain Compton scattering?

  • Coop
  • · Replies 10 ·
Replies
10

Graduate Pauli exclusion principle and position-state restriction

  • hokhani
  • · Replies 7 ·
Replies
7

Graduate Calculating Matrix Representation of 11><11 for 2 Qubits

  • Getterdog
  • · Replies 5 ·
Replies
5

Graduate Dirac Delta Function: Is delta(x-y) the Same as delta(y-x)?

  • eahaidar
  • · Replies 7 ·
Replies
7

Graduate Necessary axioms to derive solution to QHO problem

  • snoopies622
  • · Replies 2 ·
Replies
2

Graduate Multiple entangled particles and no-communication

  • Ookke
  • · Replies 4 ·
Replies
4

Graduate Finding work function from photoelectric effect data

  • bobbles22
  • · Replies 1 ·
Replies
1

Graduate Angular momentum in the 3D Schrodinger eqn with a central force

  • hideelo
  • · Replies 8 ·
Replies
8

Graduate No-cloning and uncertainty principle

  • nomadreid
  • · Replies 7 ·
Replies
7

Graduate Step potential with E<V: reflection coefficient and probability current

  • hnicholls
  • · Replies 2 ·
Replies
2

Graduate CHSH experiment with SPOT detector: polarization detection and cos² formula

  • midix
  • · Replies 5 ·
Replies
5

Graduate Delbrück scattering results in ether?

  • nomadreid
  • · Replies 10 ·
Replies
10

Graduate Solving Matrix Eigenvalue Equation for ψ_{200} and ψ_{210} States

  • M. next
  • · Replies 1 ·
Replies
1

Undergrad How can the atomic radius of any atom be accurately calculated?

  • omax
  • · Replies 8 ·
Replies
8

Graduate Do electrons jump instantaneously between energy levels or transition gradually?

  • BOAS
  • · Replies 4 ·
Replies
4

Graduate Questions on the Dirac equation

  • Matterwave
  • · Replies 11 ·
Replies
11

Graduate Why scalar fields become operators in QFT and how particles are defined

  • HomogenousCow
  • · Replies 5 ·
Replies
5

Graduate Permenance of Collapsed Wave Function Spin State

  • ChiralWaltz
  • · Replies 6 ·
Replies
6

Graduate Older nuclear structure models.

  • carllacan
  • · Replies 1 ·
Replies
1

Graduate Group theory and quantum mechanics

  • journeyman1986
  • · Replies 2 ·
Replies
2

Graduate J.J. Sakurai: Error of 2nd Order in d x' Eq (1.6.24)

  • omoplata
  • · Replies 5 ·
Replies
5

Undergrad Why do electrons drop energy levels?

  • jonland82
  • · Replies 11 ·
Replies
11

Graduate At What Scale Does Quantum Mechanics Impact CPU Functionality?

  • need_aca_help
  • · Replies 1 ·
Replies
1

Graduate What is the quantum anti-zeno effect?

  • James MC
  • · Replies 9 ·
Replies
9

Graduate Approx. Solution To Quantum Harmonic Oscillator for |x| large enough

  • Chem.Stud.
  • · Replies 6 ·
Replies
6

Graduate Commutator expectation value in an Eigenstate

  • Matterwave
  • · Replies 19 ·
Replies
19

Graduate Sequential measurements of conjugate observables

  • atyy
  • · Replies 21 ·
Replies
21

Graduate Can someone explain the ignorance ensemble theory

  • batmanandjoker
  • · Replies 1 ·
Replies
1

Graduate Will the Casimir Effect Operate Between Bolt Threads at 10nm?

  • jaiii
  • · Replies 1 ·
Replies
1

Graduate Sum of the probabilities equals 3 in bipartite covariance ?

  • jk22
  • · Replies 7 ·
Replies
7

Graduate Are two electrons in an hydrogen orbital positionally dependent ?

  • xortdsc
  • · Replies 6 ·
Replies
6

Graduate Is Quantum Entanglement Instantaneous for All Observers?

  • Terdbergler
  • · Replies 21 ·
Replies
21

Graduate Entanglement entopy and area law

  • arpharazon
  • · Replies 3 ·
Replies
3

Graduate Operator transformation under infinitesimal unitary transformation

  • M. next
  • · Replies 3 ·
Replies
3

Graduate Path integrals as usually presented - what does it tell us?

  • pellman
  • · Replies 4 ·
Replies
4

Graduate Unruh Effect and Temperature Differentials

  • trendal
  • · Replies 5 ·
Replies
5

Graduate Quantization Rule for Planetary Motion?

  • Mahasweta
  • · Replies 1 ·
Replies
1

Graduate Delayed-choice multi entanglement swapping

  • StevieTNZ
  • · Replies 3 ·
Replies
3

Graduate Dirac ket-bra simplification over here.

  • M. next
  • · Replies 7 ·
Replies
7

Graduate Hesienburg Uncertainity Principal

  • Tigersharkmks
  • · Replies 8 ·
Replies
8

Graduate Superposition in the Macro World - Why Not?

  • T2theB
  • · Replies 20 ·
Replies
20

Graduate QM and a new way to calculate probabilities

  • DaTario
  • · Replies 8 ·
Replies
8

Graduate Quantum numbers and Pauli exclusion principle in molecules

  • Bob65
  • · Replies 5 ·
Replies
5

Graduate Ground State Energy of quantum oscillator

  • PsychonautQQ
  • · Replies 1 ·
Replies
1

Graduate Two interfering antennas with single photon radiation

  • user3
  • · Replies 2 ·
Replies
2

Graduate When do Newtonian mechanics breakdown

  • shanepitts
  • · Replies 3 ·
Replies
3

Graduate Wave Function Terminology - Are these synonyms?

  • shanepitts
  • · Replies 4 ·
Replies
4

Graduate Conserved Charges of Stress Energy Tensor

  • WarDieS
  • · Replies 2 ·
Replies
2

Graduate Infinite Potential Colliding with Wave Function: Is it Correct?

  • rmfw
  • · Replies 1 ·
Replies
1

Graduate Multiple universes in cosmology and quantum mechanics

  • greypilgrim
  • · Replies 6 ·
Replies
6

Graduate Large N Expansion: Getting Started

  • metamathphys
  • · Replies 3 ·
Replies
3

Graduate Calculating Probability Density in Quantum Mechanics

  • Tigersharkmks
  • · Replies 3 ·
Replies
3

Graduate States are or aren't unit vectors?

  • nomadreid
  • · Replies 16 ·
Replies
16

Graduate Is Yang-Mills scale invariant?

  • nonequilibrium
  • · Replies 9 ·
Replies
9

Graduate Can you combine wavelengths to ionize atoms

  • ranger275
  • · Replies 2 ·
Replies
2

Graduate Do London dispersion forces play a role in biological replication?

  • Eagle9
  • · Replies 5 ·
Replies
5

Graduate Quantum Zeno effect survival probability derivation gaps

  • James MC
  • · Replies 9 ·
Replies
9

Graduate Q3: How do we measure rotational degrees of freedom in quantum mechanics?

  • bkent9
  • · Replies 4 ·
Replies
4

Graduate Does QM violate the causality principle?

  • HamzahA
  • · Replies 4 ·
Replies
4

Graduate Is it possible to use Quantam entanglement to study event horizon

  • kkragam
  • · Replies 7 ·
Replies
7

Graduate What is the disparity in the dimensionality of angular momenta?

  • Matterwave
  • · Replies 8 ·
Replies
8

Graduate Does spin have a spatial direction

  • aaaa202
  • · Replies 6 ·
Replies
6

Graduate Double slit experiment with electrons - detector at one slit

  • fizixfan
  • · Replies 8 ·
Replies
8

Graduate Mermin's One-Measurement Refutation of Local Hidden Variables

  • stevendaryl
  • · Replies 3 ·
Replies
3

Graduate Atomic Probability Densities Always Even?

  • physicsphreak2
  • · Replies 1 ·
Replies
1

Graduate Why does scaling the uncertainty principle give frequency not angular frequency?

  • alejandrito29
  • · Replies 7 ·
Replies
7

Graduate Some questions about spin in relation to the stern-gerlach experiment

  • xortdsc
  • · Replies 8 ·
Replies
8

Graduate Non-Relativistic QED Textbook Reference - Zag

  • Zag
  • · Replies 2 ·
Replies
2

Graduate Finite well penetration depths dependence on Well Length

  • PsychonautQQ
  • · Replies 1 ·
Replies
1

Graduate Quantum Explanation of Magnets

  • Hornbein
  • · Replies 3 ·
Replies
3

Graduate C from quantum first principles?

  • nomadreid
  • · Replies 4 ·
Replies
4

Graduate Connecting classical plane waves to quantized EM field operators

  • MisterX
  • · Replies 1 ·
Replies
1

Graduate Is it possible for a wave function to have a discontinuous first derivative?

  • LagrangeEuler
  • · Replies 14 ·
Replies
14

Graduate Use of component tensor product in quantum mechanics?

  • jk22
  • · Replies 2 ·
Replies
2

Graduate Storing data in quantum spaces.

  • pondzo
  • · Replies 5 ·
Replies
5