User Tools

Site Tools


equations:dirac_equation

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
Next revision Both sides next revision
equations:dirac_equation [2018/03/26 17:15]
jakobadmin
equations:dirac_equation [2018/04/16 09:11]
jakobadmin [Intuitive]
Line 1: Line 1:
-====== Dirac Equation: ​\quad (i\gamma_\mu \partial^\mu - m ) \Psi =0 $ ======+<WRAP lag> (i\gamma_\mu \partial^\mu - m ) \Psi =0 $</​WRAP>​
  
 +====== Dirac Equation ======
  
-</​note>​ 
  
 +<tabbox Intuitive> ​
 +The Dirac equation describes how the state of a relativistic (= fast moving) quantum system with half-integer spin changes in time.
  
-<tabbox Why is it interesting?> ​+The analogous equation for systems without spin is the [[equations:​klein-gordon_equation|Klein-Gordon equation]].
  
-The Dirac equation ​is the correct equation of motion that describes free [[basic_notions:spin|spin]] $1/2$ particles.+If the system only moves slowly, the Dirac equation ​becomes ​the [[equations:pauli_equation|Pauli equation]]. 
  
- +<​tabbox ​Concrete
- +
-<​blockquote>​In fact, Dirac'​s equation for the electron must be rated, alongside the [[equations:​maxwell_equations|Maxwell]] and [[equations:​einstein_equation|Einstein equations]],​ as one of the Great Field Equations of physics.<​cite>​page 289 in "The Emperors new Mind" by Penrose</​cite></​blockquote>​ +
-<tabbox Layman>  +
- +
-<note tip> +
-Explanations in this section should contain no formulas, but instead colloquial things like you would hear them during a coffee break or at a cocktail party. +
-</​note>​ +
-   +
-<​tabbox ​Student+
  
   * A nice discussion can be found in [[http://​www.quantumfieldtheory.info/​website_Chap04.pdf |chapter 4 of Klauber'​s Student Friendly QFT book]]   * A nice discussion can be found in [[http://​www.quantumfieldtheory.info/​website_Chap04.pdf |chapter 4 of Klauber'​s Student Friendly QFT book]]
Line 32: Line 25:
  
   * For a nice description,​ see section 7.4.3 "​Diracology"​ in the book The Conceptual Framework of Quantum Field Theory by Duncan   * For a nice description,​ see section 7.4.3 "​Diracology"​ in the book The Conceptual Framework of Quantum Field Theory by Duncan
-<​tabbox ​Researcher+<​tabbox ​Abstract
  
 <note tip> <note tip>
 The motto in this section is: //the higher the level of abstraction,​ the better//. The motto in this section is: //the higher the level of abstraction,​ the better//.
 </​note>​ </​note>​
 +
 +<tabbox Why is it interesting?> ​
 +
 +The Dirac equation is the correct equation of motion that describes free [[basic_notions:​spin|spin]] $1/2$ particles.
 +
 +
 +
 +<​blockquote>​In fact, Dirac'​s equation for the electron must be rated, alongside the [[equations:​maxwell_equations|Maxwell]] and [[equations:​einstein_equation|Einstein equations]],​ as one of the Great Field Equations of physics.<​cite>​page 289 in "The Emperors new Mind" by Penrose</​cite></​blockquote>​
  
 <tabbox Definitions>​ <tabbox Definitions>​
Line 43: Line 44:
   * $\partial _{\mu} $ denotes the partial derivative and $ \gamma_{\mu} \partial^{\mu}$ stands for a sum using the Einstein sum convention, i.e. $\gamma_{\mu} \partial ^{\mu} =  \gamma_0 \partial^0 - \gamma_1 \partial^1 -\gamma_2 \partial^2 -\gamma_3 \partial^3$,​   * $\partial _{\mu} $ denotes the partial derivative and $ \gamma_{\mu} \partial^{\mu}$ stands for a sum using the Einstein sum convention, i.e. $\gamma_{\mu} \partial ^{\mu} =  \gamma_0 \partial^0 - \gamma_1 \partial^1 -\gamma_2 \partial^2 -\gamma_3 \partial^3$,​
   * $m$ denotes the mass of the particle,   * $m$ denotes the mass of the particle,
-  * $\Psi$ is either the wave function of the spin $1/2$ particle if we use the Dirac equation in a particle theory, or describes the spin $1/2$ field if we work in a field theory,+  * $\Psi$ is either the wave function of the spin $1/2$ particle if we use the Dirac equation in a particle theory, or describes the spin $1/2$ field if we work in a field theory. In any case$\Psi$ is not a vector but a [[advanced_tools:​spinors|spinor]]. ​
   * $\gamma_\mu$ are the Dirac gamma matrices.   * $\gamma_\mu$ are the Dirac gamma matrices.
   ​   ​
equations/dirac_equation.txt · Last modified: 2023/04/02 03:11 by edi