Derivation of the low-energy effective Hamiltonian
44747
Finding the effective Hamiltonian in a certain subspace
54548
Expectation value for $\frac{1}{r}$ in the $|nlm\rangle$ state of hydrogen
48068
Any good resources for Lagrangian and Hamiltonian Dynamics?
10190
Dirac equation as Hamiltonian system
3603
Lagrangian and Hamiltonian EOM with dissipative force
7152
Using the uncertainty principle to estimate the ground state energy of hydrogen
155484
Quantum mechanical picture of "electrons orbiting the nucleus"
96880
How to obtain Hamiltonian formalism and phase space for Lagrangian with second-derivatives?
68951
Normalization of the overlap $\langle x'|p'\rangle$
159017
Bohr-Sommerfeld quantization condition from the WKB approximation
44302
Deriving the Coulomb force equation from the idea of photon exchange?
9965
Deriving or justifying fundamental constants
94173
Deriving the Lagrangian for a free particle
59594
Binding energy and mass
29952
Time-ordering vs normal-ordering and the two-point function/propagator
158526
Finding a "Principle of Least Action" equivalent statement for Hamiltonian Mechanics
55231
Is there a simple way of finding the eigenstates of the creation and annihilation operator in QM?