The h Bar

General chat for Physics SE (physics.stackexchange.com). For M...
Jan 4 12:43
That the action is just some waves but more complicated sounds like an attractive interpretation
Jan 4 12:42
1
Q: Connections between the path integral formulation and the Fourier transform

User198I am just learning abut the Path integral formulation and it seems to me that there is a connection, at least conceptually, to the Fourier transform. In the Path integral formulation we sum over all possible paths a particle can take between two points. Each path contributes with a phase factor d...

Apr 8, 2024 12:16
https://www.youtube.com/watch?v=kcSYV8bJox8
So... photoelectric effect, it is easy to see how light quantas excite electrons to produce electric currents. But are their other theories knew for other transformations, such as light induced magnetic field changes without polarisations, or maybe even gravitophoto effects?
Feb 24, 2024 09:41
Thoughts about the mass renormalisation problem of naive treatment of quantum gravity. What if there is a ultraviolet cutoff in the spectra of momenta just enough to prevent all the powers of mass terms in the perturbation to blow up hence ensuring convergence?
Feb 13, 2024 11:48
how many worlds occupy in a quantum multiverse?
Jan 10, 2024 14:10
Geometry precision in stargazing and astronomy, all replaced by computer calculations
Aug 6, 2023 18:10
have been reading the recent tetraquark finding lately, not sure what yet about some of the blips in the right end of the spectra
Jun 22, 2023 17:21
@Mad I don't know, maybe for example, look at some LHC data, try out some pattern statistics and then use the relations work out in the data about the particles to inspire the maths (or at least some postulates) to formulate a new theory?
Jun 22, 2023 17:14
@Mad Fruit for thought, what if the overreliance on maths ends up modelling our way of interpreting experiment results to fit the mathematics?
Jun 22, 2023 12:54
@ Acuriousmind "Are you sure he had not sped by a quantum $\hbar$ amount?"
Jun 22, 2023 12:51
lol
Jun 12, 2023 14:04
I see
Jun 12, 2023 14:00
e.g. measure a spin along z and then x give different result from x then z
But measuring a spin along z, then wait a bit, and then measure along z again, gives +1 for both measurments
Jun 12, 2023 14:00
hmm... but if you let it then evolve a bit and then measure it again the same way, you still get the same result. That "stickiness to evolution" is probably the strange bit
Jun 12, 2023 13:58
Probably the biggest mystery of quantum mechanics...
though if they do the maths will get very hard, imagine $[A,A] \neq 0$...
Jun 12, 2023 13:58
Some thoughts about the measurement problem
Why don't *experimentally*, repeated measurements of the same kind give different outcomes?
Jun 11, 2023 13:16
but I wonder if some theories actually has a mathematical structure that ensures its optimality at least internally speaking, so that within the formulation, it rules out any better candidate theories
Jun 11, 2023 13:16
We usually use occams razor to select good theories to test in experiments
Jun 11, 2023 13:16
Ok tidying up some thoughts, I think lately I had been thinking about the notion of "there is no better theory according to the mathematics formulation" type of questions
Jun 11, 2023 13:10
Is is possible that a hilbert space formulation just happened among the possible theories, to match the best to the standard deviations obtained from experiments in heisenberg uncertainty principle?
Jun 11, 2023 13:07
a. The spin operator has an analogue to 3-vector direction (name the form $\sigma \cdot \hat{n}$) owing to how the basis of the state vectors are chosen (everything just alinear combination of spin up spin down state vectors), that allows them to as if split into 3 components for each spatial direction nicely as if it is a 3-vector
b. Postulate on why quantum mathematical formulation agree so well with experiment – The basis is chosen such that any significant experiment results just happens to pop up in the spectra of many Hermitian operators
Jun 11, 2023 13:05
So... lately my quantum mechanics had been going rusty so I restudy the whole thing using Susskind's theoretical minimum, and then I notice the following maths trivia
Jun 9, 2023 15:37
Do we have experimental evidence of some probablistic outcomes do not quite follow a linear evolution (e.g. noisy outcomes which barely fits a linear model)
There's a diffusion current treatment of the schrodinger equation, but it is not clear if it captures enough nonlinearity in the operators https://www.sciencedirect.com/science/article/abs/pii/037596019290061P
Jun 9, 2023 15:28
Not expecting this will go anywhere
Formulating measurement procedure as a projection operator on the state seemed sound though
 

 Mathematics

Associated with Math.SE; for both general discussion & math qu...
Apr 22, 2024 06:48
$n(1-z_0) = t(p_2-p_1)$ is the constraint. In fact, this has some relationship with the twin primes conjecture
Starting with solving the equation $p_1x+p_2y=1$
If p1,p2 are twin primes and n is even, then the equation has solutions $(1,1)$ and solves the goldbach's conjecture
For the general goldbach conjecture which ask if every integer can be written as the sum of two primes, this only occurs if the prime gap is a multiple of the given integer
So the whole question resolves to, is there an integer for every gap between primes
Apr 17, 2024 12:31
Prove the continuum hypothesis is independent from the axiom of dependent choice
Feb 28, 2024 14:43
"cool. What does a symbolic python of mathematics swallow whole?"

Hmm... try, the following
$$\int_{\text{A$\to$ End}} \frac{\text{Snake Lemma}}{\text{max (ker, coker)$\circ$ (\{A,B,C,$\dots$\})}}$$
Provided the direct limits that is key to define the integration in all the relevant subspaces are defined, the integral converges and you can swallow a lot of short exact sequences with simply integration with SymPy
Feb 27, 2024 14:30
Feb 27, 2024 13:57
@Jakobian Got it, thanks
Feb 27, 2024 13:27
@Jakobian yep
Feb 27, 2024 13:19
@Tapi Sure
Feb 27, 2024 13:18
@Jakobian $(a,c) \in L$ and $(c,b) \in R$, so we basically have pairs $((a,c),(c,b))$ defining a map from the left argument to the right one
Feb 27, 2024 13:11
yeah, $c_{a,b}$ for each $a,b$ with $aDb$, so one c each time
Feb 27, 2024 13:06
@Jakobian typo yeah
Feb 27, 2024 12:22
In any semigroup, D-class is defined to be there is c such that a L c and c L b
If we permutate all the possible a,b in S, we get abstractly, a structure consists of all possible pairs of (aLc, cLb) which is almost like a automorphism between pairs of elements. Question ia, is this always have the be the same as the automorphism semigroup of a given semigroup?
Jan 23, 2024 14:03
Integrals of the form
$$\int \frac{1}{f(x)+g(f(x))+g(x)}$$ remains difficult
Jan 7, 2024 09:44
Dec 16, 2023 07:43
What does that say about NP and P I wonder?
Dec 16, 2023 07:43
Start with the bounds [1/4,7/2] and let e be the number we are interested in estimating. Now fit some family of polynomials P_n to the two numbers in the bound. Then we get the liouville criterion 1/q^2. Now use a program to half the interval each time towards e, then we can make this liouville crtierion arbitrarily small from 1/q^4, 1/q^6 , .... Thus we have a polynomial procedure to approach e at arbitrary accuracy, therefore the lower bound of transcendence degree of e is 1.
Dec 9, 2023 06:33
Consider a countably long sequence of real numbers $\{a_n\}$ which exhibits divergence due to oscillatory phenomena of its terms (that is, there is a upper and lower bound on where the $a_n$ s are). Can the set of all such sequences along with the set of all convergent sequences, be combined to form a large set that preserves as much of the field properties of real numbers?
Nov 27, 2023 15:23
- It follows that the first infinity is an even prime number bigger than any number, and there are obviously infinitely many of them
Nov 27, 2023 15:22
**Lemma**
Proving that by the fundamental theorem of algebra, any product decomposition of integers is finite
- We have n, Suppose there is a m > n, n can said to be finite relative to m. Then
- By fundamental theorem of algebra, n can decompose into many factors
- We know that (-1)(-1) = 1
- The product of positive factors is a multivariable monotonically increasing function f, so f(x1,x2,x3,x4, ...) = n for given n exists
- 0n = 0, so to have nonzero n, all terms has to be positive or negative
Jun 10, 2023 14:51
Ok figured out
$f'(x) = 1+ f(x)^2$
The left hand side gives how much the right hand side increments so we can roughly have something like
$1+f(x)^2, 1+f(x+1+f(x)^2)^2, 1+f(x+1+f(x)^2+1+f(x+1+f(x)^2)^2)^2, ...$
Then working through the cases $f(x) > 0$, $f(x) < 0$ and $f(x) = 0$, the graph traced out by the increments will rise and fall without limit, while locally linear at $f(x)=0$ thus producing the familiar tan x curve
Jun 10, 2023 13:57
Thinking about functional equations lately
The solution of $f'(x)=1+f(x)$ is straightforward if we knew about trigonometric identities, but supposed we knew nothing about them, what will be a first approach to investigate the possible nature of the solution?
 

 The Symposium

A Party Space for Philosophy.SE! Both philosophy and mundane c...
Jul 31, 2023 18:29
possibly interesting, cannot find any questions ask about it and its relationship with say metaphysics though