Given a topological space and a group acting on it, the images of a single point under the group action form an orbit of the action. A fundamental domain or fundamental region is a subset of the space which contains exactly one point from each of these orbits. It serves as a geometric realization for the abstract set of representatives of the orbits.
There are many ways to choose a fundamental domain. Typically, a fundamental domain is required to be a connected subset with some restrictions on its boundary, for example, smooth or polyhedral. The images of a chosen fundamental domain under the group action then tile the space. One general construction of fundamental domains uses Voronoi cells.
In many-body theory for electronic structure, fermions experience a force resulting from Pauli Exclusion. So by extension, would quarks and other subatomic fermions experience this force?
If so, what is the "high energy" physics side of the story to forces arising from exchange rules? Is it a...
It's strange to me that multiplication and division are considered fundamental operations.
It makes sense for me that addition is a fundamental operation but multiplication is just like a function or algorithm that takes several numbers and apply additions. This is true even for multiplication...
Hello! I am a bit confused by the formula ##dU = TdS - PdV##. If I want to compute for example ##\frac{\partial U}{\partial V}## I obtain ##-P##, but how should I proceed to obtain, for example ##\frac{\partial U}{\partial P}## or ##\frac{\partial P}{\partial T}## which are not obvious from the...
Suppose you periodically receive samples of a periodic waveform at fixed instances in time Δt. It is known ahead of time that the periodic waveform will have a fundamental frequency component of 50Hz or 60Hz, but perhaps with some higher order harmonics present.
What is the easiest way to go...
Homework Statement
Let
\begin{equation*}
f(t) = 2 + \cos\left( 3t - \frac{\pi}{6} \right) + \frac{1}{4}\cos\left( \frac{1}{2}t + \frac{\pi}{3} \right) + \sin^2(t)
\end{equation*}
Determine the period ##T## and fundamental frequency ##\omega_0## of ##f## and draw images of its amplitude and...
Homework Statement
Show that Dx∫f(u)du = f(x) Where the integral is evaluated from a to x. (Hint: Do Taylor expansion of f(u) around x).
Homework Equations
None
The Attempt at a Solution
I have
... = Dx(F(u)+C) = Dx(F(x-a)+C) = dxF(x) - dxF(a) = f(x)-f(a). My problem is that it should be...
So for what I understand, when a star collapses, the electrons do not like to overlap their quantum states because of the pauli exlusion principle. Is this different from an E&M force? If so, then why isn't it a fundamental interaction? All forces are made of a combination of the 4 fundamental...
Charles Link submitted a new PF Insights post
Fabry-Perot and Michelson Interferometry: A Fundamental Approach
Continue reading the Original PF Insights Post.
Hi, this is a newbee question. Does the Fundamental Theorem of Calculus supply a visual (graphical) way of linking a function (F(x)) with its derivative (f(x))? That is, the two-dimensional area under a curve in [a,b] for f(x) is always equals to the one-dimensional distance F(b)-F(a)? If...
I don't understand the difference between the Jeans Mass and the fundamental mode. Both are reaching till the horizon but according to me is the Jeans mass not oscillating. So what is the relation between a Jeans mass and the fundamental mode of the acoustic waves?
So out of the concepts such as mass, momentum, angular momentum, fields, etc what is the most fundamental in physics?
I'm thinking energy since the lagrangian shows up almost everywhere, not just in classical mechanics.
But I'm not sure since I haven't looked deeply into all fields of physics...
Homework Statement
A vibrating tuning fork of frequency 512 Hz is held over a water column with one end closed and the other open. As the water level is allowed to fall, a loud sound (resonance) is heard at specific water levels. Assume you start with the tube full of water, and begin steadily...
Homework Statement
The spoke of a wire wheel is 9.5 cm long, 3.5 mm in diameter, and under tension of 2100 N. The wire is made of steel of density 7860 kg/m3. When struck with a metal tool at its center, the spoke rings at its fundamental frequency. What is that frequency?
Homework Equations...
1. Homework Statement
The wire cable supporting the mast of a sailboat has a length of 12 m and a linear mass density of 350 g/m. When pushed sideways at its midpoint with a force of 160 N, the cable deflects by 9.5 cm. What is the frequency of the fundamental mode of vibrations on this...
This is an old qual question, and I want to see if I have it right. I had virtually no instruction in homology despite this being about 1/4 of our qualifying exam, so I am feeling a bit stupid and frustrated.
Anyway,
I am given a space defined by three polygons with directed edges as...
I was listening to a lecture by Peter Thiel. He argued that "scientists never make any money", and are "always deluded into thinking they live in a just universe that will reward them for their work, and this is probably the fundamental delusion that scientists tend to suffer from in our...
The assumption states that all states (or I shall say micro-states) are equally probable. This is the foundation where we construct our theories on entropy, different kind of distributions, etc.
Is there any explanation for this assumption? Or why did the scientists that time take this...
As far as I know, we regard the electromagnetic force, gravity, strong and weak interactions as the four fundamental forces.
We know that Newton's law of gravitation does not perform as well as Einstein's general relativity. Scientists are now using energy-stress tensor to describe...
Hi everyone. Very orderly forum you have here. I'd like to ask a few philosophical questions which are very fundamental to QM.
Firstly I assume we all agree that a fundamental particle - imagine an electron or quark - has multiple inherent properties which are all separable from each other, such...
I've tried repeatedly to get clear, succinct definitions of the following terms over and over again, but invariably the definitions provided clash, and I'd like to put an end to that. The terms I am trying to define clearly are:
- Relation
- Definition (Mathematical definition)
- Function
-...
Homework Statement
A space explorer travels in a spaceship with v = 0.9c. She goes from Earth to a distant star that is 4 light years away (again, measured from Earth). What is the distance measured by the explorer and how long will she say it took her to get there?
Homework Equations...
in broken supersymmetry every fermion has a super partner that is a boson, with same internal quantum numbers, except mass. i.e superpartner of an electron is a selectron, which is a boson.
in QFT gauge bosons are force carriers. gauge bosons with mass create a force that is short-ranged...
Homework Statement
F(x) = (integral from 1 to x^3) (t^2 - 10)/(t + 1) dt
Evaluate F'(x)
Homework Equations
Using the chain rule
The Attempt at a Solution
Let u = x^3
Then:
[((x^3)^2 - 10) / (x^3 + 1)] ⋅ 3x^2
*step cancelling powers of x from fraction*
= (x^3 - 10)(3x^2)
= 3x^5 - 30x^2
I am...
I am trying to establish a Rationalist approach to Physics as a side project, and have taken Hamilton's Principle as one of the few postulates in my work. I've developed the concept enough to arrive at the usual stuff, like the Euler-Lagrange equations, Newton's First Law and Nöther's Theorem...
I am reading the book, Basic Abstract Algebra by P.B. Bhattacharya, S.K. Jain, and S.R. Nagpaul ... ... and am currently focused on Chapter 2: Integers, Real Numbers and Complex Numbers ...
I need help with an aspect of the proof of the Fundamental Theorem of Arithmetic in Section 1.3 ... ...
I am reading the book, Basic Abstract Algebra by P.B. Bhattacharya, S.K. Jain, and S.R. Nagpaul ... ... and am currently focused on Chapter 2: Integers, Real Numbers and Complex Numbers ...I need help with an aspect of the proof of the Fundamental Theorem of Arithmetic in Section 1.3 ... ...The...
The proofs of the Fundamental Theorem of Calculus in the textbook I'm reading and those that I have found online, basically show us:
1) That when we apply the definition of the derivative to the integral of f (say F) below, we get f back.
F(x) = \int_a^x f(t) dt
2) That any definite integral...
Homework Statement
"Under mild continuity restrictions, it is true that if ##F(x)=\int_a^b g(t,x)dt##,
then ##F'(x)=\int_a^b g_x(t,x)dt##.
Using this fact and the Chain Rule, we can find the derivative of
##F(x)=\int_{a}^{f(x)} g(t,x)dt##
by letting
##G(u,x)=\int_a^u g(t,x)dt##,
where...
Homework Statement
A rope has an end fixed and the other is passing through a pulley and has a body attached to it. The fondamental frequency of the rope is initially ##f_1=400 Hz##. If the body is then put in water the fondamental frequency of the rope becomes ##f_2=345 Hz##. If the linear...
Homework Statement
How many 3 digit numbers can be formed from 0 to 3 without repition
Homework EquationsThe Attempt at a Solution
What I did first is
H = number of choices for the hundreds place
T = number of choices for the tens place
U = number of choices for the units digit
H = 3...
I try to understand topic of turbomachinery. Would someone like to make some guidance?
In that page I cannot understand some parts.
1) What does it mean by "above two conditions" in "Viscous effects must unfortunately be neglected, as it
is generally impossible to satisfy the above two...
So, I've been looking at this chart
Only Electro-magnetic force is carried by massless particle - photon. And it propagates at the speed of light. Now take Weak and Strong force. They are carried by bosons and gluons. They have mass. So, what is the speed of propagation of Weak and Strong...
Homework Statement
I understand how to find the resonant frequency of a closed pipe but when the thickness of the walls varies, the resonant frequency varies. Is there a formula that i can use to find the resonant frequency of a closed pipe given the length, temperature, speed of sound and...
Please anyone explain that why frequency is more fundamental than wavelength inspire wavelength and frequency depend upon each other again frequency and wave number are also depends upon each other
Then why we take the frequency as independent of wave number
Homework Statement
How can i find the fundamental frequency of a closed piep (measuring cylinder) experimentally/ physicaly. I have done the maths and found the frequency but i want another way to prove this other than simply playing the calculated frequency back at the measuring cylinder. I...
Homework Statement
I have made a plot of a given .wav file in Matlab. The problem asks: find the fundamental frequencies of the 3 vibrating strings, and identify some of their harmonics.
Homework Equations
3. The Attempt at a Solution [/B]
So I made a Matlab plot of the power spectrum over...
I'll put you in context for the sake of simplicity before asking my question. Say we have the following homogeneous linear system:
x'=Ax
Let A be 2x2 for simplicity. Then the general solution would look like:
x(t) = αa + βb
And a fundamental matrix would be:
Ψ(t) = ( a , b )
What...
When you are in research behind your desk, are you using c=h=g=1?
I think this is common now. Everyone is doing it.
Is there anyone, who is not doing it?
And if, why?
Hey everyone,
I am currently in the middle of research for a science fiction /fantasy novel where the magic system is based on the ability of a group of people to manipulate the four fundamental forces of physics. Of these four, coming up with ways that individuals could manipulate gravity and...
i: B to Y is an inclusion, p: X to Y is a covering map. Define $D=p^{-1}(B)$, we assume here B and Y are locally path-connected and semi-locally simply connected. The question 1: if B,Y, X are path-connected in what case D is path-connected (dependent on the fundamental groups)? 2 What's the...
I'm talking about equation 22,
Does anyone know how to derive this? It's Marin Mersenne's formula for fundamental frequency, but I'm perplexed as to how he derived it.
L would be the length, F would be force, and μ would be mass per unit length.
f is the frequency
Thanks
The 7th note has a frequency of L/3 and the 12th has a frequency of L/2. What is the ratio of the two frequencies?
I feel like this is really easy but I don't know how to solve this.
What is the difference between "Physics" (1 volume, 1156 pages) and "Fundamental University Physics" (3 volumes) by Alonso Finn? Is the former 3 volumes bound as one or a revised edition?
Hi everybody, after studyng a little bit of nuclear physics I have noticed that many reactions (α,β,γ...) end with the new particles in excited states which rea¡main in those for a little time before going to the fundamental.
I don't know why this happens instead of going directly to the...
Time is a fundamental quantity. but we actually measure time with change in the position of objects. for example one orbit which Earth completes is a year. one rotation of Earth is a day, one second is defined as 9192631770 cycles of the radiation corresponding to the transition between the two...
Is there a book containing fundamental proofs such as any number of the form x^2n beeing even and such.
I know this is very vague, so I must apologize.
Thanks for any help.
So the matrix is just a row vector
\begin{bmatrix}3 & 4 & 0\end{bmatrix}
My problem, is that I get the nullspace as having to 2 dimensions, and the row space as having 2 dimenions, but that adds up to 4 dimensions, when it should add up to three. What simple thing am I missing?
Null space...