Undergrad Confused by Notation? Perturbation Theory Explained

Click For Summary
The discussion focuses on the conditions under which the expression equals the product * in the context of perturbation theory. Participants suggest examining matrix representations to clarify the notation and underlying principles. The confusion arises from the intricacies of Dirac notation and operator multiplication. Understanding the linearity and properties of operators is essential for resolving these notational challenges. Clarifying these concepts is crucial for those new to perturbation theory.
Getterdog
Messages
83
Reaction score
6
TL;DR
Sum and product of Dirac operators
Looking at. <psi|AB|theta>, under what conditions would this be equal to <psi|A|theta> * <psi|B|theta> I’m just getting into perturbation theory
and am running into confusing notation. Thanks john
 
Physics news on Phys.org
Getterdog said:
Summary:: Sum and product of Dirac operators

Looking at. <psi|AB|theta>, under what conditions would this be equal to <psi|A|theta> * <psi|B|theta> I’m just getting into perturbation theory
and am running into confusing notation. Thanks john
My first thought is to look at matrix representations.
 

Thread 'Two equivalent statements of time reversal symmetric Hamiltonian'

Time reversal invariant Hamiltonians must satisfy ##[H,\Theta]=0## where ##\Theta## is time reversal operator. However, in some texts (for example see Many-body Quantum Theory in Condensed Matter Physics an introduction, HENRIK BRUUS and KARSTEN FLENSBERG, Corrected version: 14 January 2016, section 7.1.4) the time reversal invariant condition is introduced as ##H=H^*##. How these two conditions are identical?
View full post »

Similar threads

Undergrad Degenerated perturbation theory
  • · Replies 3 ·
Replies
3
Views
1K
Graduate Confusion about creation/annihilation operators with interaction
  • · Replies 1 ·
Replies
1
Views
658
Undergrad Degenerate Perturbation Theory
  • · Replies 7 ·
Replies
7
Views
3K
Graduate TD perturbation - state initially in continuous part
  • · Replies 49 ·
2
Replies
49
Views
5K
High School Time independent perturbation theory
  • · Replies 3 ·
Replies
3
Views
1K
Undergrad Confused about perturbation theory
  • · Replies 3 ·
Replies
3
Views
1K
Time independent perturbation theory
  • · Replies 7 ·
Replies
7
Views
1K
Undergrad Time Dependent Sinusoidal Perturbation Energy Conservation
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Learning DFT: Inhomogeneous Electron Gas (Hohenberg) Question
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad Time dependent perturbation theory
  • · Replies 2 ·
Replies
2
Views
1K