Questions tagged [probability]

For questions about probability, probability theory, probability distributions, expected values and related matters. Purely mathematical questions should be asked on Math.SE.

744 questions
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Electron density in DFT (*ρ*(r)) and probability density (wave function squared)

Are the electron density in density functional theory, ρ(r), and probability density, defined as wave function squared, the same quantities?
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E. T. Jaynes' subjectivism vs measurement of distributions

In his paper, E. T. Jaynes argues that entropy is a measure of our ignorance about a system. As such, the probability distribution of states $\{p_k\}$ has to be chosen in the most unbiased way, thus ...
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If the probability that an alpha will deflect is $1/10000$, for $n$ layers, is the probability is only $1/10000n$?

I have attached a picture of an extract I read on Wikipedia (also in the AQA A-Level Physics specification and textbook). It says that 1/10000 alpha particles deflected in the alpha particle ...
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Radiative Transport Equation scattering phase density probability term question

The development of Radiative Transport Equation has a contribution term called the scattering phase density probability function. It account to scattering events from photons from a different solid ...
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Finding the expression for probability density (the Klein Gordon equation)

Source: Quantum Field Theory for the Gifted Amateur by Tom Lancaster, Stephen J. Blundell. I am struggling to understand the logical step from the outline of the 'proof' in the footnote, to the fact ...
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Can Quantum Mechanical Potential have a Probability Distribution

I am currently in my second semester of undergraduate quantum mechanics. We have recently starting discussing two particle systems, usually in relation to spin interactions. In all of our calculations,...
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Understanding the calculation of expectation value

The expectation value (in sense of discrete probability) can be thought of as $$\left<a\right>=\frac{1}{N}\sum\limits^{N}{Â }\psi$$ where $N$ is the number of experiments. As the number of ...
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Can an electron of an atom be found anywhere? Does it need energy to happen? [closed]

According to quantum mechanics it should be possible. But can it happens when it has so small probability to occur? also if it can happens that means that energy must be provided in order to the ...
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Notation in a question on probabilities and particle counting

I'm working through Stephen Barnett's book on quantum information and have come across the following question (1.5, for anyone keeping track at home) A particle counter records counts with an ...
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Probability of WaveFunction [closed]

A particle is confined in a one dimensional box of length $a$. What is the probability of finding the particle at $x = a/4$? I know that the wave function is written as $$y= A\sin([(\pi x)/a]$$...
I was learning Basic Quantum mechanics. I cam across the fluid equation in QM, which suggests $\Psi^*\Psi$ is probability density function. Consider the two statements below Probability will change ...
I'm reading a paper (Rapp, 1968) that treats quantum mechanically the problem of a particle $A$ "hitting" an harmonic oscillator made of two particles, $B$ and $C$: \$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,...