Does this wavefunction make sense?

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The discussion centers on the wavefunction defined by ##\left| \psi (x) \right|^2 = e^{-ax^2+1}+e^{-bx^2-1}##, where a and b are real, positive numbers. The key point is that while the wavefunction can be normalized, there are instances where ##\left| \psi \right|^2 > 1##, which raises questions about its interpretation. Participants clarify that ##|\psi^2|## represents a probability density, not a probability, allowing values greater than one in localized regions while still adhering to normalization constraints over an interval. Understanding this distinction resolves the confusion regarding the wavefunction's validity.

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Isaac0427
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Hi all!
Consider a wavefunction, where ##\left| \psi (x) \right|^2 = e^{-ax^2+1}+e^{-bx^2-1}## where a and b are real, positive numbers that satisfy normalization (they are purpously inside the exponent). Even if it is normalized, there are still 2 spots that ##\left| \psi \right|^2 > 1## which makes no sense. What is going on here?
Thanks!
 
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Recall that ##|\psi^2|## is a probability density. The probability for finding a particle in an interval ##[a,b]## is ##\int\limits_a^b|\psi^2|\mathrm{d}x##. This integral is what must be ##\le 1## (where it equals one when you integrate over all of space). To convince yourself, take one of the Gaussian functions you wrote and normalize it, evaluate at ##x=0## and start increasing ##a##. Despite still being normalized ##|\psi^2|## can be made arbitrarily large. Why is that alright?
 
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Haborix said:
Recall that ##|\psi^2|## is a probability density. The probability for finding a particle in an interval ##[a,b]## is ##\int\limits_a^b|\psi^2|\mathrm{d}x##. This integral is what must be ##\le 1## (where it equals one when you integrate over all of space). To convince yourself, take one of the Gaussian functions you wrote and normalize it, evaluate at ##x=0## and start increasing ##a##. Despite still being normalized ##|\psi^2|## can be made arbitrarily large. Why is that alright?
Ah, I get that. I was confused as I thought of it as a probability and not a probability density.
 

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