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.
1,473 questions
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What is the probability that the Solar system encounters a black hole?
What is the probability that the Solar system encounters a black hole?
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Relationship between momentum and probability current in Dirac equation
I would expect that for a given eigenstate with energy $E$, the density of momentum $\mathbf{p}$ and the probability current $\mathbf{j}$ at any point would be related as:
$\mathbf{p}=\frac{E}{c^2}\...
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What's the probability distribution of when the ball will fall from Norton's dome?
Suppose our world is completely described by Newtonian mechanics. All the materials are rigid and can be cut infinitesimally.
There exist scenarios where the future is intrinsically probabilistic. ...
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Are fields in particle physics some wave functions, that is amplitude of probability?
In particle physics, there are fields for fermions, typically labelled $\psi(x)$, and fields for scalar, typically labelled $\phi(x)$, which are functions of the space-time coordinate $x=(t, x, y, z)$....
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What does it mean by pdf ( probability density function) integrated minimum and maximum value of a progress varaible?
I am reading a paper on combustion and I come across this staement which I don't understand how they arrived it ?
A progress variable is generally defined as a linear combination of species mass ...
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Probability a system at temperature $T$ has more than a certain energy
In the Feynman Lectures I, Ch. 42, it is stated that the probability of a system at temperature $T$ having energy $W$ above the average energy is $e^{-W/k_BT}$. This is used to derive the rate of ...
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What causes amplitudes to interfere?
I have started working through Quantum Mechanics section of the Exercises for the Feynman Lectures on Physics, but I got stuck on one of the questions. The question is about an idealized version of an ...
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Characterization of Markovianity, Gaussianity, and color for noise processes
Consider a noise process $\xi(t)$ that has some statistics in time. There are various ways to characterize such a process, 3 being Markovianity (independence from history), Gaussianity (Gaussian ...
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Clarification on equation 5 in Feynman's 1948 path integral paper
In the 1948 paper "Space-Time Approach to Non-Relativistic Quantum Mechanics", Feynman presents his formulation of quantum mechanics in terms of path integrals. I've been reading through it ...
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Why randomness taking a specific outcome at that time? [duplicate]
Im a 16 year old and this question stuck in my mind. I cant find apt answer.
Imagine we tossed a coin, we have 50-50% chance to get heads or tails. We say its random but truly we can predict the ...
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Why is the PDF in Maxwell Distribution of Speeds simply NOT the derivative of the Boltzmann Distribution?
It is written in Atkin's Physical Chemistry
It implies that the fraction of
molecules with velocity components $v_x$, $v_y$, $v_z$ is proportional to an exponential
function of their kinetic energy, $...
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Can quantum effects that result in an object taking infinitely many possible paths apply to macroscopic objects?
If according to quantum physics, a particle moving from point A to point B takes every possible path. Is it possible to apply this to macroscopic objects?
For instance if I throw a ball up in the air, ...
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Is it true that quantum mechanics technically there is a 50% chance of any event happening? [closed]
This is most definitely a very stupid question. According a friend of mine, there is a 50% chance of any event happening according to quantum superposition and quantum probabilities.
My counter ...
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Correlation matrix of spin glass model
Consider a mean-field spin glass model (e.g., the Sherrington-Kirkpatrick model or the spherical spin glass):
$$ H_J(\sigma)= -\frac{\beta}{\sqrt N} \sum_{i,j=1}^N J_{ij}\,\sigma_i\,\sigma_j - h \sum_{...
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Fermi's golden rule for total transition rate [duplicate]
Im following Mark Thomson's Modern Particle Physics section 2.3.6 but I have question in the proceedure followed from equation 2.46 to 2.48
Starting from equation 2.46:
$$d \Gamma_{fi} = \frac{1}{T} ...
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