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[NOTES/EM-03005] Charged Particle In Electromagnetic FieldExpression for the Lagrangian for a charged particle in electromagnetic field is given. Gauge invariance of the Lagrangian furnishes an example quasi invariance under the gauge transformations. $\newcommand{\pp}[2][]{\frac{\partial #1}{\partial #2}}\newcommand{\dd}[2][]{\frac{d#1}{d#2}}$ |
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24-03-26 22:03:15 |
[NOTES/QM-09008] Perturbation Expansion in Interaction pictureThe equation \[i\hbar\frac{d U(t,t_0)}{dt} = H'_I(t) U(t,t_0).\] obeyed by the time evolution operator in the interaction picture is converted into an integral equation. A perturbative solution is obtained from the integral equation following a standard iterative procedure. $\newcommand{\DD}[2][]{\frac{d^2 #1}{d^2 #2}}\newcommand{\matrixelement}[3]{\langle#1|#2|#3\rangle}\newcommand{\PP}[2][]{\frac{\partial^2 #1}{\partial #2^2}}\newcommand{\dd}[2][]{\frac{d#1}{d#2}}\newcommand{\pp}[2][]{\frac{\partial #1}{\partial #2}}\newcommand{\average}[2]{\langle#1|#2|#1\rangle}$ |
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24-03-24 19:03:37 |
[NOTES/QM-09004] Stationary States and Constants of Motion$\newcommand{\DD}[2][]{\frac{d^2 #1}{d^2 #2}}\newcommand{\matrixelement}[3]{\langle#1|#2|#3\rangle}\newcommand{\PP}[2][]{\frac{\partial^2 #1}{\partial #2^2}}\newcommand{\dd}[2][]{\frac{d#1}{d#2}}\newcommand{\pp}[2][]{\frac{\partial #1}{\partial #2}}\newcommand{\average}[2]{\langle#1|#2|#1\rangle}$ The eigenstates of Hamiltonian are called stationary states.In a stationary state all observable quantities are independent of time. The dynamical variables which commute with Hamiltonian are called constants of motion. The average values of constants of motion in any state do not change with time. |
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24-03-24 19:03:48 |
[NOTES/QM-09007] Interaction Picture of Quantum Mechanics$\newcommand{\DD}[2][]{\frac{d^2 #1}{d^2 #2}}\newcommand{\matrixelement}[3]{\langle#1|#2|#3\rangle}\newcommand{\PP}[2][]{\frac{\partial^2 #1}{\partial #2^2}}\newcommand{\dd}[2][]{\frac{d#1}{d#2}}\newcommand{\pp}[2][]{\frac{\partial #1}{\partial #2}}\newcommand{\average}[2]{\langle#1|#2|#1\rangle}$ |
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24-03-24 19:03:00 |
[NOTES/QM-09003] Solution of TIme Dependent Schrodinger Equation$\newcommand{\DD}[2][]{\frac{d^2 #1}{d^2 #2}}$ $\newcommand{\matrixelement}[3]{\langle#1|#2|#3\rangle}$ $\newcommand{\PP}[2][]{\frac{\partial^2 #1}{\partial #2^2}}$ $\newcommand{\dd}[2][]{\frac{d#1}{d#2}}$ $\newcommand{\pp}[2][]{\frac{\partial #1}{\partial #2}}$ A scheme to solve the time dependent Schr\"{o}dinger equation \begin{equation} \label{eq01} i\hbar \dd{t}\ket{\psi} = \hat{H} \ket{\psi} \end{equation} is described. The final solution will be presented in the form, see \eqref{eq14} \begin{equation} \ket{\psi t} = U(t, t_0) \ket{\psi t_0} \label{eq16} \end{equation}where |
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24-03-23 05:03:26 |
[NOTES/SM-01001] Thermodynamic Coodinates |
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24-03-20 15:03:27 |
[NOTES/CM-02003] From Newton's EOM to Euler Lagrange EOM Euler Lagrange equations are obtained using Newton's laws and D' Alembert's principle. |
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24-03-15 06:03:32 |
[NOTES/CM-02001] Limitations of Newtonian MechanicsSome limitations of Newtonian mechanics are pointed out. |
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24-03-15 04:03:24 |
[NOTES/QFT-01001] Examples of Classical FieldsAfter recalling the analytical dynamics briefly, several examples of systems with infinite degrees of freed are given. |
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24-03-10 09:03:01 |
[NOTES/EM-07013] Conservtion of Electromagnetic Field Momentum.*
The equation of continuity appears in different branches of physics. It represents a local conservation law. In order to be consistent with requirement if special relativity every conserved quantity must come with a current which gives the flow of the conserved quantity across a surface and the two must obey equation of continuity. Taking the example of momentum conservation, we briefly discuss the interpretation of stress tensor giving flow of momentum per unit time as a surface integral. The surface integral, in turn, gives the force on the surface.
$\newcommand{\pp}[2][]{\frac{\partial #1}{\partial #2}} \newcommand{\dd}[2][]{\frac{d#1}{d#2}}$ |
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24-03-02 11:03:19 |