Are These Expressions for Probability Current Density Equivalent?

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SUMMARY

The discussion centers on proving the equivalence of two expressions for probability current density in quantum mechanics. The first expression is defined as j(r,t) = h'/2im(Ψ*ΔΨ - (ΔΨ*)Ψ), while the second is j(r,t) = Re[Ψ* (h'/im) ΔΨ]. The key to the proof involves recognizing the relationship between the real and imaginary parts of complex numbers and applying integration by parts. The solution confirms that the two expressions are indeed equivalent through mathematical manipulation.

PREREQUISITES
  • Understanding of quantum mechanics concepts, specifically probability current density.
  • Familiarity with complex numbers and their properties.
  • Knowledge of mathematical operations such as integration by parts.
  • Basic grasp of the reduced Planck's constant (h' = h/2π).
NEXT STEPS
  • Study the derivation of probability current density in quantum mechanics.
  • Learn about the properties of complex functions and their real and imaginary components.
  • Explore integration techniques, particularly integration by parts in mathematical physics.
  • Review the implications of the reduced Planck's constant in quantum equations.
USEFUL FOR

Students and professionals in physics, particularly those focusing on quantum mechanics, as well as anyone interested in mathematical proofs related to complex functions and probability densities.

qwijiboo
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Hi folks!

Can someone tell me how to solve the following... I'd really appreciate it.

Homework Statement



Show that the below two expressions for probability current density are equivalent.

j(r,t) = h'/2im([tex]\Psi^{*}[/tex][tex]\Delta\Psi[/tex]- ([tex]\Delta\Psi^{*}[/tex])[tex]\Psi[/tex]]

j(r,t) = real part of [[tex]\Psi^{*}[/tex] (h'/im) [tex]\Delta\Psi[/tex]]


Homework Equations


h' is the reduced Plancks constant h/2pi


The Attempt at a Solution




 
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You should really give us your thoughts (or at least a guess) on this. But if c is a complex number, what's the relation between Im(c) and Re(c/i)? And you may also want to think about integration by parts.
 
I'm sorry... but I figured it out. Its a pure math problem. Sometimes my brain just ceases to work!

RP of the second equation is {j(r,t) + [j(r,t)]*}/2 substituting ,we get the first equation.

Thanks anyways for replying to my post.
 

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