instruction stringlengths 31 24.3k |
|---|
More specifically, starting from $\langle 0| \phi (x) \phi (y) |0 \rangle$ I have arrived at the expression:
$D(x-y)=\langle 0| \phi (x) \phi (y) |0 \rangle= {\Large\int \int} \frac{d^3p \cdot d^3q}{(2 \pi)^3} \frac{1}{2E_q} \delta^{(3)}( \vec p - \vec q) e^{i(q \cdot y -p \cdot x)}={\Large\int \int} \frac{d^3p \cdot ... |
According to my knowledge the exclusion principle won't affect it, so it will jump to the muonic 1s orbit (strongly deformed by the electrons' repulsion).
The electrons fill the electron 1s orbits (also distorted).
So it would become like a He, but much heavier and easier to ionize.
|
As many of you have probably known there was a famous Hafele–Keating experiment, which was about a plane traveling the globe in order to prove predictions of special relativity and general relativity.
After the plane has landed a time difference was observed. It is widely accepted that clock in the frame of reference o... |
During the course of a textbook problem, I obtain the following (simplified to keep only important elements) :
$$\int^{b}_{-b}dy\int^{b}_{-b}dy' \space exp\{A(y^{2}-y'^{2})\} \space \delta(y-y')$$
where the answer is $2b$
My instinct would be to treat the problem as such :
$$\int^{b}_{-b}dy\int^{b}_{-b}dy' \space f(y, ... |
Find acceleration in the following system :
This was a solved example in the book (*) which had steps as follows:
$$ W_1 - T_1 = M_1 a $$
$$ W_2 - T_2 = M_2 a (**)$$
$$ T_1 R - T_2 R = I \alpha $$
$$ T_1 - T_2 = I \frac{ \alpha}{R}$$
Now, combining equations,
$$ W_1 - W_2 - \frac{I\alpha}{R^2} = (M_1 +M_2) a$$
Usi... |
I often heard that electron-muon scattering is a QED process. So I suppose that muon is a field in QED. However, when looking at the QED Lagrangian, it is basically
F^2 + psi D_A psi
where D_A is the gauge covariant derivative (with gamma matrices). Since psi already represents the electron, my question is, where is th... |
A vector field $X=X^\mu\partial_\mu\in\mathfrak{X}(M)$, where $M$ is a (pseudo-)riemannian manifold with a generic metric tensor $g_{\mu\nu}$, is a conformal Killing vector field if the conformal Killing equation \eqref{CKE} is satisfied:
$$
\tag{1}\label{CKE}\mathcal{L}_Xg_{\mu\nu}=X^\lambda\partial_\lambda g_{\mu\nu}... |
So I'm in year 10 (9th grade for the Americans) and I just had a question about physics.
What is the difference between atoms, particles and matter?
Are they all the same thing and people just use the terms interchangibly or are they all completely different.
Thanks!
|
I am trying to find the matrix representation of the $\mathfrak{su}(1,1)$ $K_{-}$, $K_{+}$ and $K_0$ matrices commonly used in quantum optics defined as $$K_{-}=\frac{1}{2}\hat{a}\hat{a},\quad K_{+}=\frac{1}{2}\hat{a}^{\dagger}\hat{a}^{\dagger}\quad K_{0}=\frac{1}{4}(\hat{a}\hat{a}^{\dagger}+\hat{a}^{\dagger}\hat{a}).$... |
I am studying physics in high school and am trying to understand electronics.
Using Ohms law I calculated VIRP values for a simple circuit with three 1000 ohm resistors and a 9V battery. I then set up the same circuit on a breadboard and tested the Voltage and current using a multimeter but the values seem to be signif... |
How can someone use Raman Spectroscopy to obtain information for the phonon modes of a crystal? I am asking for some paper that contains information about Raman Spectroscopy and Phonons from an experimental point of view.
|
My knowledge in vector space and quantum mechanics is weak and I am trying to understand and make sense of the question that I asked.
It will be very helpful if someone could explain it to me in a conceptual and deeper sense.
|
Thanks to Andrew Steane and Pulsar in this topic I understood that in a frame with constant proper acceleration, each hyperbola in $T-X$ diagram demonstrates a constant position while each line passing through origin demonstrates constant time.
That is, from viewpoint of an accelerated frame, two simultaneous events i... |
I am having trouble with the units used in the Hamiltonian of the Ising model. I have search several notes, I have three examples in the picture below
No one states explicitly what the units of the following terms are: $S_i, J$ and $ H,B,h$ (these should all represent a magnetic field :)
Do the spin variables $S_i$ h... |
My question is given that a capacitor creates a two charged sides, by the electrons jumping from one plate to another thereby making one having an excess of electrons making it negative and the other positive. How can this process occur, as a capacitor will also create and electric field that has an orientation going f... |
I am having trouble understanding solutions of the Dirac equation. From what I understand, the probability current four-vector is $J^\mu=\bar\psi\gamma^\mu\psi=\psi^\dagger\gamma^0\gamma^\mu\psi$.
The problem is that the solutions that I have seen of the Dirac equation are said to be
$$\psi^{(1)} = e^{\frac{-imc^2t}{\h... |
Let $\psi(x)=Ne^{iax -\frac{m^2x^2}{2} -ibt}$ and I want to compute the possibility of momentum $p$. By definition : $\langle p^2\rangle=\int_{-\infty}^{\infty}\psi^*p^2\psi dx$. Is that equivalent to $\langle p^2\rangle=\int_{-\infty}^{\infty}(p\psi^*)(p\psi) dx= \int_{-\infty}^{\infty}(p\psi)^*(p\psi) dx$?
Is there a... |
What are the physical realities of the different quantum gates? I am particularly interested in how the CNOT gate works on the inside as well as how the Hadamard gate works. The Hadamard gate to me is strange because my assumption on superposition was that a particle left undisturbed would naturally assume a superposit... |
In quantum mechanics, in Dirac notation an inner product is denoted as $\langle A|B\rangle$ and one fundamental postulate is given as follows:
$\langle A|B\rangle = \langle B|A\rangle ^*$
If I were to consider $|A\rangle $ and $|B\rangle $ as vectors represented by column matrices, then the inner product between two ve... |
My system is a bunch of charged particles in a 1 dimensional harmonic potential. This is a computer simulation, and what I get is a list of the positions and velocities of each particle at every time step.
When the simulation is in equilibrium i.e. it has been running for a long time, the speed distribution looks somet... |
I've been studying some error analysis on An Introduction to Error Analysis: The Study of Uncertainties in Physical Measurements by John R. Taylor for an introductory course. At the beginning of chapter 4 I read that in some cases we use statical analysis to evaluate the uncertainty, in other cases we use the propaga... |
I understand that light travels in a straight line unless gravity says otherwise. However, if it were theoretically possible to keep the energy in a photon without having any directional movement, what would happen? Would the photon dissipate and just transfer its energy to a nearby particle?
|
The motivation behind my question is that it seems very unlikely that a chunk of metal would "randomly" reach escape velocity and fly away from the Earth, but it happens thanks to NASA and other space programs. If the second law of thermodynamics regarding entropy is statistical, can it be broken on a larger scale?
|
Imagine a DC circuit with small but non-zero resistance in wires and large resistance in a single resistor in series with the battery, all ohmic.
Connecting the battery I imagine a surge of electrons from the - plate due to high concentration of negative charges. Using Coulombic concepts I intuit a movement on average ... |
I've been wondering this for a while now, and have thus far only come across answers that seem to use an equation as an explanation. I've also looked at Huygens' principle (albeit not in-depth), but this doesn't make much logical sense to me.
I'd sincerely appreciate if anyone could shed any light on the topic for me (... |
In class we had an exercise, where for a non-conductiong spherical shell given a potential inside and out we had to find a charge distribution and E field inside and out, with a charge distribution $\sigma =Q\cos\theta$, so the sphere is kind of like a charged dipole, where positive charge is on the upper and negative ... |
Wikipedia tells me that a bolt of lightning releases roughly 1 GJ of energy, but I'm guessing that's along the entire length of the bolt and that most of it is dissipated as heat and light to the surrounding atmosphere.
Don't know much about the physics behind this, but assuming the bolt is 20km long that's about 50 KJ... |
Often in many elementary and secondary school books frequented by students aged 6 to 13 years old still write $\mathrm{Kg}$ instead of $\mathrm{kg}$. Many teachers give to the students this notation $\mathrm{Kg}$ that I used when I was a child, i.e. with a capital $\mathrm{Kg}$. Also the newspapers, television, ... use... |
As the gravitational field inside Earth outer core is relatively weak can the angular momentum of Earth's outer core be high enough to cause lighter elements or compounds being deposited in Earth's deeper regions and denser matter being moved upwards? And as Earth's rotation is faster on the equator does that mean ther... |
If a very brief wave (perhaps a single photon, or maybe a soliton?) is at its minimum (a 'node') when it encounters a detector, would it still be detected?
|
I have read, if the sun disappeared it would take 8 minutes before this could be detected on Earth due to speed of gravity being $c$. Of course, the sun can't disappear. Perhaps realizing this impossibility, people write of the sun exploding instead. But if the sun literally exploded the mass would still be present for... |
From the post demonstration of expand perturbations of metric,
I understand the full demo below excepted for the last result, i.e :
$$
\sqrt{-g}=\sqrt{-\operatorname{det} b}\left(1+\frac{1}{2} \operatorname{tr}\left(b^{-1} h\right)-\frac{1}{4} \operatorname{tr}\left(b^{-1} h\right)^{2}+\frac{1}{8} \operatorname{tr}^{2}... |
Before you answer, read this: Say you are on an elevator, and for some reason, when in it and you jump, you have a different velocity from the elevator, say the elevator is at 15 MPH and you are jumping at 5 MPH. The elevator catches up faster than it does when you and the elevator are both at the same speed, right? Al... |
In the book Principles of Lasers by Orazio Svelto, at chapter 4.3 "Wave Reflection and Transmission at a Dielectric Interface", the author tells that
If the wave is initially in the medium of refractive index n_1 and it is normally incident on the surface, the electric field reflectivity is
$r_{12}=\frac {n_1-n_2} {n_... |
As every event in the universe can be reduced to interaction between particles via the 4 fundamental forces, can the same be applied to time? Could the flow of time be reduced to a particle that causes an instant of time, or is time an emergent phenomenon of the fabric or the nature of space? Or could time be an emerge... |
This is pure speculation. The title of the question is a quote from Zeidler's book on QFT p.141:
In the setting of noncommutative geometry, physical states are primary and space-time is secondary.
This is around the discussion of sub-Planck length and time scales. However, for the simplest case of nonrelativistic qua... |
A mass is hanging from a string that is attached
to the ceiling. A second piece of string (identical
to the first) hangs from the lower end of the
mass
State and explain which string will break if:
a the bottom string is slowly pulled with ever
increasing force
b the bottom string is very abruptly pulled down.
For a th... |
I am looking into pendulum physics for a real life application. In short I need to have a reasonable estimate of the horizontal stress applied by a swing mechanism supported by a wooden structure.
I started with an ideal pendulum representation (weightless string + bob of mass $m$, no damping or further complications)... |
I was studying parallel and series connections for circuit and came a cross a problem that could not understand.
Now look at this problem:
lets say current (I) is coming from the left:
the current (I) will be separated looking for the lowest resistance (I mean Highest (I) will be at the lowest Resistance), but I1 will... |
According to some books, diffraction occurs when there is an obstacle whose linear dimensions are comparable to the wavelength of light.
This is true also for a hole or a slit through which the light passes.
My question is the following: shall we consider all the linear dimensions of an obstacle (height, width, thickne... |
Consider a group of charged point(at least considered as such in this non-relativistic limit) particles such electrons,protons
, nucleii alone in an empty infinite universe and NOT considering any internal structure nor spin nor magnetic interaction though can consider spin as far as symmetry, antisymmetry
requirements... |
I am reading: https://en.wikipedia.org/wiki/Optical_resolution
But am confused if adding a supplemental lens to an imaging system (in this case my phone) would change the amount of information resolved.
The second part of this is question is, does adding a lens change the amount of information you are able to resolve r... |
I am wondering what would be the result if a piece of copper were to suddenly lose all its valence electrons, or in other words, if a piece of copper was to suddenly become a collection of copper cations.
Since the Coulomb force between all the positively-charged copper atoms/cations should immediately start to push th... |
The maximum amount of work makes complete sense for me as from the premise of the derivation being that we are considering a reversible process. However, what does it mean to say maximum amount of non-expansion work? (*)
My personal research attempts:
In a chemistry discussion forum (**), they say that non expansion ... |
In 1916, Schwarzschild published his $R$-metric solution that differs from the $r$-metric solution we are all familiar with. The relation between $R$ and $r$ is $R^3=r^3 + α^3$ with $r$ been the distance marker and $\alpha$ being the well-known $α=2GM$.
I quote from his paper: "Actually Mr. Einstein’s approximation for... |
The Hamiltonian for a simple 2-band model after $k\cdot p$ is:
$H(k)=\begin{bmatrix}
\frac{E}{2}+\frac{\hbar^2 k^2}{2m} & \frac{\hbar}{m}k\cdot P \\
\frac{\hbar}{m}k\cdot P & -\frac{E}{2}+\frac{\hbar^2 k^2}{2m}
\end{bmatrix},$
where $P=\langle u_n | H_k | u_m \rangle$.
In 2D, one may use $k=\sqrt{k_{x}^2+k_{y}^2}$.
In ... |
I'm hoping to double major in math and physics. I'm currently taking graduate math courses and undergrad physics courses.
I'm having a really hard time with my Electromagnetism class. A lot of the problems being given have solutions that aren't really detailed enough for me to make sense of them. They will write down t... |
If I am aboard a spacecraft and have with me two identical metal spheres having rest mass $= m$, what happens to the gravitational force between these two spheres as the space craft velocity approaches the speed of light. According to Newton, $F = G*m1*m2/r2$. Does $F$ between my two spheres increase according to this... |
A toy was rolled off the table at 10 m/s and landed 5 m from the table. The same car is rolled off the same table at 15 m/s.
Would the time the car was in the air increase, decrease or stay the same? Explain why you picked the answer you did.
Would the distance the car landed from the table increase, decrease or st... |
In the circuit, the capacitors are said to be connected in parallel. Why is that so?
Edit: The switch will be closed and C2 is fully charged by C1 and no more current will flow between C1 and C2. The question asks for the voltages and charges hold by C1 and C2. In the solution, it is mentioned that C1 and C2 are conne... |
This questions stems from Anna's answer here:
https://physics.stackexchange.com/a/578929/230132
Quoting her, she says an electron bound to a nucleus is not a quantum entity, the entire atom is. And she adds that as such the two are not separable.
My knowledge of QM is rudimentary, but I think I understand what she mean... |
This question also stems from Anna's answer here: https://physics.stackexchange.com/a/578929/230132
Quoting her, she says an electron bound to a nucleus is not a quantum entity, the entire atom is. She adds that as such the two are not separable.
And she says this is also true of a molecule, i.e. it is one single quant... |
Depending on the data, the tension in the measurement of the Hubble constant $H_0$ is up to 9 percent. This corresponds to about 5 sigma. I am interested how this standard deviation is calculated.
|
So I am a newbie to QM, and coming from math, I believe I am not understanding some key points in bra-ket notation.
So given a quantum state $\psi$, I understand that $|\psi \rangle$ is a just a Hilbert space notation for a function. Now, we say that
$$\langle \psi_n | \psi_m \rangle = \int \psi_n^* \psi _m dr$$
Which ... |
This is about photons of very large wavelength, say radio frequencies on the lower end of the electromagnetic spectrum.
Given a wavelength of several hundreds of meters, it seems to me the carrying photon could easily meet a moving obstacle right in the middle of it.
In my picture, I assume the photon to have a size, w... |
I have a scalar complex field: $\phi(x) = \phi_{1} + i \phi_{2}\;$ so $\;\phi^{*}(x) = \phi_{1} - i \phi_{2}$ where $\phi_{1}, \; \phi_{2}$ are real scalar fields.
Then I have something like $\;\phi^{*}\overset\leftrightarrow{\partial_{\mu}}\phi \;$. What does this $\;\overset\leftrightarrow{\partial_{\mu}}$ means?
(P... |
Since according to the unitarity principle of quantum mechanics the total amount of information in the universe is conserved over time, how was this information generated in the first place? And how is this question related to the fact that the (gravitational) entropy of the very early universe was very low?
|
As gravitational potential energy is well good to tell us everything, but why we need to use gravitational potential
|
I reviewed part of my notes in the quantum mechanics class, and still have a few questions about the variational derivation of the Schrodinger's equation:
The variational principle says that the expectation value of $H$ in any state $⟨\psi|H|\psi⟩$ is greater or equal to the ground state energy $E_{min}$. Given the arb... |
I was watching this crash course by Geek Lesson on Quantum Mechanics specifically for Quantum Harmonic Oscillator and [at 1:54:54] when video shows the plot of probability density for different states in Quantum Harmonic Oscillator the probability density is shown more at ends. The speaker gives explanation like this
... |
Say I have a conductor with hollow cavity inside with no charge inside the cavity. Now the conductor is subjected to external electric field. Now we know that electric field inside conductor is zero, hence the inside cavity is equipotential. Hence for the given charge distribution above, there will be E-field inside c... |
I was wondering why the net horizontal force on the sled was $2 \cdot F$ rather than just $1 \cdot F$. Is that the case because of the reactionary force of tension on the pulley? I think my understanding of tension is off.
|
It is known that in a curved spacetime, due to the center of mass not beeing clearly defined object can change position using contortions. However an object generates its own gravity and changes in spacetime propagate only with lightspeed. So could an object swim in its own field if it was fast enough?
|
As a teenager, back in the late 1980s or possibly very early 1990s, I came across a very nice popular science book on particle physics in my hometown library, that I probably borrowed and read at least three times during high school. Many years later, when I took Quantum Field Theory II at university, it struck me how ... |
Imagine a photon passes by a stationary atom in a large void of empty space. We know that the gravity of the atom will bend the path of the photon. It will also blue shift as it approaches the atom and redshift again as it leaves.
Light is energy and according to general relativity it too bends spaces creating a grav... |
I understand that the $\Lambda$CDM cosmological model is mainly built over general relativity, however many of it's features invoke quantum field theory (such as inflation). I find this confusing because they are distinct theoretical frameworks with, apparently, no clear connections.
Is there a deeper way to look at th... |
I should express the momentum of the system of $N$ particles and the kinetic energy in terms of Jacobi coordinates:
$$\vec \xi_n = \frac{m_1 \vec r_1+\dots+m_n\vec r_n}{m_1+\dots+m_n}-\vec r_{n+1}, \quad (n=1,\dots, N-1), $$
$$\vec \xi_N = \frac{m_1 \vec r_1+\dots+ m_N \vec r_N}{m_1+\dots+m_N }.$$
So, I've already fou... |
I am seeking the minimum eigenvalue and the eigenfunction of the following Hamiltonian on interval $[0,1]$;
$$\hat{P}^2+ c \hat{Q}^{-1} + c (I-\hat{Q})^{-1}$$
where $c $ is an arbitrary positive constant.
$\hat{P} $ is the momentum operator and $\hat{Q}$ is the position operator.
|
I have been reading a paper about Green's function with 1d potential barrier
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.114.126602
Supplementary material Sec. II
$H=\hbar^2k^2/2m+V\Theta(x)$. Let's say the transmission coefficient and reflection coefficient are $t$, $r$ for right-going wave and $t'$, $r'... |
Can a lightsaber be made in real life?
If yes, how can you make it?
If no, why is it impossible to make it?
I know there is another question on it, but I feel like I need better answers :)
|
I am trying to learn more about the physics behind an MRI and am getting stuck trying to understand the process behind the excitation of the transverse component of the magnetisation.
From what I understand so far, you have a very strong magnetic field $B_0$ on the order of teslas which aligns the spins in a patient. D... |
I have just started studying about quantum computers (hardware side) and I am really confused about what is a quantum anharmonic oscillator. I have read somewhere that a qubit is the physical realization of a quantum anharmonic oscillator. How is it so?
|
Question:
My Book says:
ELECTRIC POTENTIAL ENERGY: Electric potential energy of a charge($q_o$) at a point(A) in the electric field due to any charge is given by the work done by an external force to displace $q_o$ without acceleration from infinity to that point(A).
$\color{red}{\text{How it is possible to displace ... |
How does one go about calculating the high-pressure airflow from an oxygen (assume 100%) bottle/supply. I only have low-pressure flow sensors available to me. I have high-pressure air coming from a bottle that is regulated to 220kPa that then goes into a venturi air mixer which expands the high pressure oxygen and mixe... |
Goldstein's Classical Mechanics proposes two ways to derive the Euler-Lagrange (E-L) equations. One is by the D'Alembert's Principle of virtual work and the second is by Hamilton's Principle of Least Action. They are both motivated quite differently.
The D'Alembert's principle is one that tries getting rid of the const... |
I have been studying Raychaudhuri equation and focusing theorem related to it. Focusing theorem says that if the strong energy condition is satisfied and rotation tensor vanishes $\omega_{ab}$=0 then rate of expansion is negative. Frobenius theorem for timelike vector says that timelike geodesic is hypersurface orthogo... |
I am struggling to understand how they have ploted some functions regarding the Ising model in the mean field approximation (Curie-Weiss model) in my lecture notes
For more details,you can see them here
https://drive.google.com/file/d/1TPFsNwuuVA5uLDNyZkJRyaFdIorUC9nn/view?usp=sharing
The hamiltonian of the model is
... |
Can we have a hypersurface in flat spacetime whose curvature is non zero?
If yes, then what is the physical significance of that?
I think there can be a hypersurface in flat spacetime with non zero curvature.For example: If hypersurface is $t-vx=constant$ which gives $dt=vdx$ then line element on hypersurface is $ds^2... |
So the UK exam board specifications (AQA GCSE) clearly state
"...the work done on the spring and the elastic potential energy stored are equal"
Here's my problem,
So work done = Force x displacement
Force = Spring constant x extension
Elastic potential energy = 0.5 x spring constant x extension squared
Extension = disp... |
How did Newton get $F=\frac{Gm_1m_2}{r^2}$?
What is intuition behind it?
What kind of experiment or thought experiment can I do to derive this?
|
I know that the length contraction can be determined by the formula: $L\sqrt{1-\frac{2GM}{Rc^2}}$
But how can we calculate the decrement in area due to the black hole??
Suppose we have a disc of area ($\pi r^2$), where $r$ is large enough so that different point in the disc experience length contraction by different a... |
(After some recommendations , I feel I need to elaborate a little bit more on my question)
So I was solving Schrodiger's equation for a step:
$$
V(x)=
\begin{cases} 0 & x<0 \\
V_0 & x>0\\
\end{cases},
$$
and in the region x $\in (-\infty,0)$ $V(x)=0$ so by solving Schrodinger's time-independent equation $\frac{d^2\... |
I mean electrons in atoms/molecules/solid bodies not count here.
I heared of an experiment measuring the degeneracy pressure of a fermion gas.
|
An electric charge experiences a force in a magnetic field only when the charge has some velocity and is moving. But velocity is always relative to a given frame of reference. It never exists on its own. If the source of the magnetic field moves, thus moving the magnetic field, and the charge is stationary wrt the eart... |
The question is simple. We know induced emf in a conducting loop due to a changing flux is given by
$$ E = -\frac{d\Phi}{dt} $$
My question is if the flux is changing only in a small part of the loop , will the emf still be induced in the loop?
Example:
|
In ch-$4$ when calculating expression of Lie derivative using Hadamard's Lemma before $(4.4)$ Frankel's do following manipulation:
$$\lim_{t\rightarrow0}\frac{\textbf{Y}_{\phi_tx}(f)-\textbf{Y}_x(f)}{t}$$
$$=\textbf{X}_x\{\textbf{Y}(f)\}$$
various symbol stands for
$\textbf{Y}$, $\textbf{X}$ are vector field on manifo... |
I'm self studying Quantum mechanics from Griffiths. Now I'm at the Harmonic oscillator potential. All my questions raised after defining the ladder operators $a_-$ and $a_+$.
If $\psi$ satisfies the time independent Schrodinger equation then too $a_-\psi$ with energy $(E-\hslash\omega)$ such that:
$H(a_-\psi)=(E-\hslas... |
Suppose an object of 75 kg falls from a height of 2 feet on land. Normally the land will feel the weight on it as 75 kg. But when the object is fallen from a height it will have some speed so at the point of contact what will be the exact or approximate weight that the land will feel?
|
I hope everyone is doing well and staying safe. So instead of simply memorizing the SUVAT equations, I wanted to find out how the equations are derived to broaden my knowledge. I'm currently a high school student who is completing university-level mathematics and somehow ended up doing questions on SUVAT and constant a... |
In several sources (e.g. this, chapter 4) I have read the following facts about Bures distance $B(\rho,\tau)$:
It has the maximal value (which is independent of the dimension of the Hilbert space) if and only if $\rho$ and $\tau$ have orthogonal support
$B(\rho\otimes \rho_1,\tau\otimes \tau_1)\geq B(\rho,\tau)$ with ... |
When using the hyraulic jack , I am totally convinced that the pressure at the initial phase must be the same in the interconnecting liquid and both surfaces where force is applied (pascal's law) , But the question is about the end state , as long as one area surface will move downward and the other is upward , so ther... |
It is said that in uniform circular motion velocity of particle is perpendicular to centripetel force, so velocity of particle won't gets affected.
When particle is about to start its motion there is no centripetel force. As soon as the particle is provided the velocity, it tries to move forwrd. This forward motion giv... |
Rate of heat transfer across a solid material kept between two environments of different temperature (Assume a wall of a house) is mentioned to be dependent on the temperature gradient, length, and thermal conductivity.
But we know that providing energy at same rate to two different substances having different specific... |
The energy of a free (nearly free) electron in a solid (say, metals) is given by $E=\hbar^2k^2/2m$ where $k$ is the momentum vector, $\hbar$ is Planck's constant and $m$ is the mass of the electron. This expression denotes a parabola. So the $E$-$k$ diagram of a such an electron is given by,
How will the $E$-$k$ dia... |
I am new to quantum computing , so my question may seem pretty vague.
I was looking for how qubits(superconducting charge qubits) are coupled together and came across capacitive coupling, can you tell me why do we need a capacitor for this, why cannot we do this using simple connections(using wires etc)?
|
Please can someone help me out with this experiment and see if this is correct?
So the experiment consists of one metal sheet that fully reflects microwaves (and is fixed in its position), and the other sheet is moveable and is a partial reflector.
How I think this experiment works is:
The H sheet that is a partial re... |
Let's say a steam turbine produces Wt. If the energy of the steam flow entering the turbine is equal to E3, and the energy of the steam flow leaving the turbine is E4, and there is an energy loss of dEf, there is also an energy loss of dq.
Are dEf and dq internal energy from the system?
Are they necessary for energy ba... |
I'm reading Purcell's Electricity and Magnetism (p. 72) and it gives an relation between the work $U$ required to assemble a charge distribution $ \rho (x,y,z) $ and potential $\phi (x,y,z) $ of that distribution:
$$U=\frac{1}{2}\int \rho \phi dV$$
It proceeds to give an equation representing the energy of a system of ... |
I'm going through Peskin & Schroeder chapter 7, and I am finding it difficult to understand how the branch cut singularity appears in the one-loop correction to the photon propagator. Essentially, the expression coming from the electron loop in a photon propagator is:
$$\hat{\Pi}_2(q^2) = - \frac{2 \alpha}{\pi} \int_0^... |
There is a lot of documentation about magnetic and electric fields being perpendicular in plane waves, I'd like to know if these two fields are perpendicular also in spherical wave.
Is it possible to find an analogous formula to the one used for plane waves?
$$\vec E=\vec B \times \vec c$$
(where $\vec c$ is a vector w... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.