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I am asking this question as a mathematician trying to understand quantum theory, so please forgive my naivety.
Systems satisfying the canonical commutation relations are naturally modeled with symplectic geometry: for example, in the discrete setting, there is a deep connection between the stabilizer formalism and aff... |
Wikipedia: "electron electric dipole moment would imply a violation of both parity invariance and time reversal invariance" ---
Yes, it is true that the electron electric dipole moment violate parity invariance.
BUT How does the electron electric dipole moment violate time reversal invariance?
|
During the phase and frequency encoding process of MRI scanner, gradient field with a gradient is applied along the direction to change kx and ky of spins at different spatial location.
I am confused how is this gradient achieved considering the magnetic field has 0 divergence.
Take ky as phase encoding direction and k... |
Consider the Friedmann equation:
$$H^2+\frac{k}{a(t)^2} = \frac{\Lambda}{3}+\frac{8 \pi}{3}\rho$$
and set the parameters for dust in either flat euclidean or open hyperbolic spatial slices with a negative cosmological constant: $\rho = \frac{\rho_0}{a[t]^3},\Lambda<0, k=0$ or $k=-1$. With that, the Friedman equation ta... |
I'm doing some introductory calculations on the D3-brane solution of type IIB supergravity. I'm considering the theory with action
$$S_{\text{IIB}} = \frac{1}{8\pi G_{10}}\int d^{10}z\sqrt{g_{10}}\left(\frac{1}{2}R_{10} - \frac{1}{2\times 5!}F_{MNPQR}F^{MNPQR} - \frac{1}{2}\partial_M \phi \partial^M \phi\right).$$
I wa... |
Under the global conformal transformation
$$\tau \rightarrow \frac{a\cdot \tau +b }{c\cdot \tau + d}, ad-bc=1, a,b,c,d\in\mathbb{Z} $$
the partition function is invariant
$$Z(\tau,\bar \tau)= Z( \frac{a\cdot \tau +b }{c\cdot \tau + d}, \frac{a\cdot \bar \tau +b }{c\cdot \bar \tau + d}, )$$
However, for a simple case o... |
In Applied Conformal Field Theory by Paul Ginsparg page 8,
the globally defined infinitesimal generators $\{l_{-1},l_0,l_1\}
\cup
\{\bar l_{-1},\bar l_0,\bar l_1\}$ resulted the finite form of the transformation
$$z\rightarrow \frac{az+b}{cz+d}, \bar z\rightarrow \frac{\bar a \bar z+\bar b}{\bar c\bar z+\bar d}$$ whe... |
There are many different ways aptamers can bind to proteins. In other words, there are multiple bound complex configurations. To test the binding affinity (free energy) of each configuration, is it possible to slightly displace the aptamer in each configuration slightly apart from the protein, and run a MD simulation u... |
The toric code model is known to have two types of "gapped" boundaries, namely, the rough boundary and the smooth boundary. See, for example, Chap. 4.1 of this beautiful review https://arxiv.org/abs/2205.05565
This fact is consistent with the "higher central charge" condition which is recently suggested in https://www.... |
I am working through some basic knowledge of second quantization. At the beginning, everything is neat and clean.
We have $|n_{1}, n_{2}, ...\rangle = a_{1}^{\dagger}a_{2}^{\dagger}...|0\rangle$, where for fermions $n_{i} = 0$ or $1$ and the creation and annihilation operators fulfill the anticommutation relation.
$\lb... |
Suppose you have a picture frame (or mirror) and it is held up by a string that goes around two posts which are at coordinates $(x_1, y_1)$ and $(x_2, y_2)$. The corners of the frame are at $(0,0)$ and $(w,0)$.
When is this system in equilibrium? (Assume no friction between the string and the posts.)
Is the answer that... |
In pictures of observed SMBH of galaxy M87there is a dark part in circle of light around it ,why?
The Event Horizon Telescope image of the core of M87 using 1.3 mm microwaves. The central dark spot is the shadow of M87* and is larger than the black hole's event https://en.m.wikipedia.org/wiki/Messier_87
|
We have two sound sources of the same amplitude but of slightly different frequencies : $f_1$ and $f_2$. When they are sounded simultaneously what would be the frequency that an observer hears ?
I have seen mixed answers for this question.
One answer is that $|f_1-f_2|$ is the frequency with which the resultant intensi... |
Suppose we have the ambient air pressure, density, speed of sound and blast overpressure. How can we use this data to get the speed of the blast wind?
Currently I simply assume that 50% of the wave's energy is kinetic, an assumption that worked for water waves, so dynamic pressure = overpressure. How right is this?
|
In classical mechanics, we know $L(q,\dot{q},t)$ and $L(q,\dot{q},t)+\frac{d}{dt}\Lambda(q,t)$ give the same Euler-Lagrange equation $\frac{d}{dt}\frac{\partial L(q,\dot{q},t)}{\partial \dot{q}_i}=\frac{\partial L(q,\dot{q},t)}{\partial q_i}$.
What I want to know is the precise corresponding statement in (classical) fi... |
can there exist a black body (theoretically) which has a cavity in it I don't mean Fery's black body I am referring to a black body which is made of a MATERIAL which has the property to emit and absorb electromagnetic waves of all wavelengths.
If it does exist then obviously it will emit radiation from both the inner a... |
Seiberg-Witten solution gives an algebraic geometrical description of the quantum moduli of 4d $\mathcal{N}=2 $ SUSY gauge theory. However, the solution seems purely constructive and does not enjoy full generality to me. I'm asking for an intuitive and thorough understanding of Seiberg-Witten theory.
In the last sectio... |
This is in reference to the paper of David Tong here. In this paper in section 2, it says
In this first section, we explain how spin impurities, coupled to bulk gauge fields, can
be thought of as Wilson lines.
Can anyone explain to me what are spin impurities exactly and how can they couple to the gauge field? Is the... |
Imagine a gyroscope falls into the event horizon of a supermassive black hole, what would happen to the gyroscope? will it remains in the same position before it falls into the event horizon?
|
Understanding how N2 and CO2 gas lasers work,
Is it possible to make a gas laser (i.e. with the right gas mix and excitation source) that:
has more than one mode of operation,
emits light in more than one band (Near-IR and UV, in this case)?
|
I was reading Fluid Mechanics by Richard Fitzpatrick. Somewhere in the book, he tried to solve inviscid flow past a semi-infinite wedge https://farside.ph.utexas.edu/teaching/336L/Fluidhtml/node76.html .
The boundry condition for the problem is:
$$\psi (r,\alpha \ \pi/2) = \psi (r, 2 \pi - \alpha \ \pi/2) = \psi (r, \p... |
In 1 (see references below), I'm trying to derive how a spinless field transforms under a conformal transformation, specifically eq. (2.41). CFT references/lectures are the most confusing I've seen EVER, even the basic definitions are a mess.
Reading 226464 and 469205 clarified bits and pieces but overall I still can't... |
In the paper by Littlejohn, 1983, the canonical Hamiltonian $h_c$ of a charged particle in electromagnetic field is given by,
$$
h_c (\vec{q}, \vec{p}, t) = \frac{1}{2m} \left[ \vec{p} - \frac{e}{c} \vec{A}(\vec{q},t) \right]^2 + e\phi(\vec{q},t) \tag{1}
$$
Here, $(\vec{q},\vec{p})$ represents the canonical position an... |
In the celebrated paper Seiberg-Witten prepotential from instanton counting by N. Nekrasov I can't quite understand some parts of section (2.3). The Nekrasov partition function is defined via
\begin{equation}\tag{NekPF}
Z(a, \epsilon) = \left\langle\exp\left\{\frac{1}{(2\pi i)^2}\int_{\mathbb{R}^4}\left[\omega\wedge\op... |
Say, I have an electron gun and ground below it (with a potential difference of U) and two coils side by side between them producing a relatively homogenous magnetic field B. If I shoot an electron laser from the electron gun, how could I calculate the minimum and maximum wavelengths of the Bremsstrahlung (Braking radi... |
Assume we have a finite string of length $L$. The string has tension $T$ and wave speed $c$.
The string is fixed at $x=0$ and connected to a massless bead at $x=L$ that can slide on a rod. The rod applies friction on the bead of the form $F_{fric} = -Cv$, where $v$ is the velocity of the bead. What are the eigenmodes o... |
The DeBroglie wavelength associated with a moving object is $$\lambda = \frac hp$$
For an object of mass 200 grams traveling with a velocity 20 m/s, it is in the order of $10^{-34}$ m. Is current technology capable of detecting matter waves of such small orders? Or are we limited to subatomic particles only? Also, is t... |
I started looking up more into quantum biology from photosynthesis to genetics mutation and how they are explained by quantum properties. my question is about the case of photosynthesis: quantum superposition offers a valid explanation as to why photosynthesis is highly efficient at converting sunlight into energy sinc... |
Say two identical capacitors are connected like this:
Two identical capacitors, each with a capacitance of 1 µF, are connected in parallel, with an open switch in between them.
If a voltage of 100V is applied only on C1 with the switch open, then it would store an energy of 5 mJ. This is the total initial energy of th... |
This question is somehow the reverse of another question.
If a quantum system $S$ is in a pure state, then we can find a wavefunction that describes $S$. This wavefunction is unique up to a phase factor. We can find it from the density matrix.
This is not possible when $S$ is in mixed state. However, I expect that for ... |
The reason told to me is due to centrifugal force. But centrifugal force is a pseudo force so how can we observe its effects like increasing radius of ring in other frame. Also as per me due to centripetal force the ring should contract. I am now confused. Should we see elongation through centrifugal force or centripet... |
I have recently started learning about physical or wave optics and one of the initial topics is Huygens' Principle.
One part of Huygens' Principle states that every point on the wavefront acts as a source of secondary spherical wavefronts
Now I have two questions:
Why is that? Why is every particle producing its own w... |
The main objective is, can we relate time in terms of a field, I know time differs in many properties from an usual field. But I always imagine time as an forward moving field and we all know it is affected by gravitational field, so can we relate time as a field?
|
I'm trying to work out what the overall acceleration of an object in non circular uniform motion.
My problem is thus,
I am trying to model the time it would take an object to fall down the inside of an arc of a circle. I imagine it as a unit circle, with my object starting from rest at (-1,0) and finishing its journey ... |
He-4 is very unusual as it’s the only nuclide that does not accept another nucleon. In other words, even if you force a proton or a neutron into He-4, it will be kicked out immediately. If you irradiate liquid helium with neutrons, it will cool the neutrons to its temperature without any neutron capture. For comparison... |
This isn't the time dilation aka rate change, but rather due to perspective change, where is Sam looking on Sally's worldline?
For example, imagine Sam is 1000 lightyears from Sally and Sally is receding at 0.1 the speed of light when Sam instantly accelerates to 0.5 the speed of light toward Sally. What equation descr... |
I'm trying to figure out a way to measure the friction coefficient between my cars tire and the surface its driving on. My current idea is to drive the car into a wall at a constant speed and figure out the current usage from the battery. What equations would I need to use to make it work this way?
|
I'm not sure if I am overcomplicating things with this question, but I have a question where we have a beryllium atom where its outermost electron is excited to the 3p orbital state. I have each quantum number for each electron in the electron config of 1s^2, 2s^1 and 3p^1, and used the equation $j=l+s$ for each electr... |
In quantum mechanics, it's well-known that observables are associated as the eigenvalue of a Hermitian operator.
My question is, is the converse also true? i.e. the eigenvalue of a Hermitian operator (which is real) must be an observable.
|
I'm confused about the theory regarding the energy- momentum relation when I consider the speed of an object being $v = c$. Using for example the relations
$$E^2 = (pc)^2 + (m_0c^2)^2$$
$$E = \gamma_{(v)}m_0c^2$$
$$\textbf{p} = \gamma_{(v)}m_0\textbf{v}$$
to find that $m_0 = 0$. I want to ask how why these equations v... |
Classical Electromagnetism defines negative charges as sinks and positive charges as sources.
Is it based on experimental distinction, or is it just that one kind of charge must be thought of as a source and the other as a sink? Will this distinction even have any effect in the mathematics?
What if there were three cha... |
I went to my car a couple days ago in the morning, and I was amazed at the patterns I found on all the side windows, shown in the attached picture. No amount of googling revealed anything similar, so I am stumped as to a possible cause. To me, these frost crystals remind me of arrows on a vector field that (just guessi... |
Take a time-oriented Lorentzian manifold $(M, g)$ where $M$ is a topological 4-manifold and $g$ a Lorenzian metric.
Assume such a spacetime contains a CTC.
Since the manifold is time-oriented, one can take a globally defined time-like vector field $u$ over the manifold.
A metric is called Purely Electric at point $p \i... |
I want to know about how we can find magnetic forces and fields in space around stars, planets, galaxies, pulsars especially pulsars. How (by what means) did determine magnetic fields around a pulsar?
|
I know that work = force times displacement with vectors ($W = \vec{F}\cdot\vec{D}$) can be calculated in the same way as a dot product, but it seems to me that it isn't really a dot product. The reason being is that they seem to be vectors in different coordinate systems. One of the vectors has a unit of length of "... |
I hope this is a good place to find an answer. Regardless, Worldbuilding looks like a great forum to follow.
I'm not a math wiz and I've tried to tackle this problem many times over the past decade or so.
I have a 3D space world, and I'm in a little space ship. I travel from point to point based on map waypoints. My ga... |
Say a body (two glued spheres will do) hits a ceiling, and the balls and ceiling are the only things in the universe. I translate the point of impact to the center of mass, calculate my lever arms, and then the sine between these arms and the $y$ force on the rigid body. From that I get the torque, and divide that torq... |
I would like to get the enthalpy as a function of temperature for BCC lithium at zero pressure.
I have performed a series of NVT simulations with 500 atoms using a Nose-Hoover thermostat at the corresponding equilibrium volumes (found using the volume average of NPT simulations) and calculated the enthalpy as $$ H = U ... |
As I humbly asked on Astronomy SE, I was wondering if there any forces or similar phenomena that scale inversely proportionally to the fourth power of the distance.
There are plenty of things that obey the inverse-square law and thus are inversely proportional to the square of the distance (light, Newtonian gravity), a... |
I am having trouble settling the difference between the math in the length contraction equation and the Lorentz transformation. Say there is a piece of wood traveling near the speed of light and you swing two axes to chop it simultaneously. If the proper length of the piece of wood is longer than the distance between t... |
Forgive the extreme, potentially unnecessary, detail, but I'm trying to include all possible info to account for all possibilities, as this has driven me mad here. I lined a baking pan with Great Value brand Heavy Duty aluminum foil, baked it with nuggets and fries on top for about 20 minutes at 420 degrees Fahrenheit,... |
EDIT: It appears there is a position taken by some, that there is no force measured and the chain drive does not shorten at all, however fast the chain is moving in the lab. I would genuinely appreciate thoughts, opinions and feedback on this alternative position.
While putting together an answer for this question "Rel... |
I am learning special relativity and still not sure how to correctly apply the time dilation formula. Take for instance the following example:
A spaceship leaves earth and travels to Alpha Centauri 4.3 ly away with the speed $v = 0.8c$. Seen from earth, the trip takes $\Delta{t} \approx5.3 $ years. Now with the time di... |
I want to apply a proper antichronous transformation to the geodesic equation in General Relativity and check if it is even or odd.
|
When I was young, I played around with whatever I could get hold on. At a time I put three balls from a ball bearing in a straight row next to each other. They were slightly magnetic, so they stuck to each other. Then I approached one end of the chain with a magnet.
To my surprise (and to that of my teachers), two ball... |
Smoke mortars were used in nuclear tests to measure the passage of the shock wave.
The passage of the shock wave could be detected by the sunlight reflected from the smoke trails being refracted through the shock wave, and high speed cameras were used to record this passage, enabling the scientists to accurately measur... |
I truly apologise if this has been asked to death somewhere, I imagine it has, but I'm yet to find an answer that completely satisfies me.
In short, I don't see why our chosen inertial frames are "correct". They're defined as those that do not require "fictitious" forces to explain motion, but that's also relative, no?... |
I have recently obtained a job in the field of radio frequency antennas and satellites, and I am interested in delving deeper into the subject. Could you recommend any books that cover these topics and are easily understandable, similar to the book Physics: Principles with Applications by Douglas C. Giancoli? It would ... |
I know that when we place an atom in an external electric field than the centre of positive charge and the centre of negative charge of the atom can separate out and thus an atom in an external electric field can have electric dipole moment and it is called induced electric dipole moment.
Is it possible for an isolated... |
Imagine a coconut of mass 1kg is falling from a 10m tall tree, the momentum is around 14kg.m/s (I don't know how to format my work but just trust me)
and then the momentum of a bullet of mass 0.01kg is fired at the speed of 1000km/h is around 2.8kg.m/s (again I'm a human calculator)
So obviously the momentum of a falli... |
S. Carroll in his book tells that the geodesic equation (together with metric compatibility) implies that the quantity $$\epsilon =-g_{\mu \nu}\frac{dx^{\mu}}{d\lambda}\frac{dx^{\nu}}{d\lambda}\tag{5.55}$$ is constant along the geodesic. I couldn't prove it. I would really appreciate if someone could help me about it.
... |
I am aware that expressions for the time-ordered expectation values of field operators can be derived using Wick’s theorem. My question is, how would one go about finding the corresponding non-time-ordered Green’s function/correlation function?
For example, if I wanted to calculate (in free real scalar field theory) th... |
This may not a good quesiton I guess, but it is very confusing while I was studying the classical states of matter :- SOLIDS, LIQUIDS, GASES.(Also please correct me wherever my concepts are wrong, and use the usual meanings of the symbols)
In solids, we have modulus of elasticity(young's modulus (Y), shear modulus(η) ... |
Second Law of Thermodynamics
From the second law of thermodynamics, the entropy of the universe must always increase. However, most explanations of entropy state that it is the measure of the number of possible microscopic arrangements or states of individual atoms and molecules of a system. Hence it is favourable for ... |
I am reading the paper “alternatives to dark matter and dark energy”, but cannot obtain one specific equation no matter how I tried. So I wrote an email to the author, the following is what he replies me.
In lines 4 and 5 when you integrated by parts you did not apply the derivatives to $g^{1/2}$. If you apply $\nabla... |
Can the electron field be excited while the photon field is not? I'm guessing the answer is no, because electrons are supposed to interact with their own electric field. I don't know about fluctuations from vacuum, though.
But how does that work anyway? Does it all come from the coupling of the two fields? How?
|
Someone asked me about how the time it takes for an event to occur might not be invariant in the context of special relativity, and the response I provided was as follows:
In special relativity, Newtonian time $t$ isn't invariant under Lorentz transformations. To illustrate this, suppose that you perform a measurement... |
I know that spontaneous parametric down conversion (SPDC) produces entangled photons in the orbital angular momentum (OAM), i.e., for a pump beam with zero OAM,
$ |\psi \rangle = | 0 0 \rangle + | 1 -1 \rangle + | 2 -2 \rangle + ... $
where the numbers indicate the OAM of the single photons.
Now If I add a spiral phas... |
The Latent Heat of vaporization of a given mass of liquid is, say, L
If we boil said mass of liquid, the vapor phase has a larger volume. Let us assume this increase in volume is ΔV.
Now by the first law of thermodynamics, Q=ΔU+W.
Rearranging, ΔU=Q-W
Work(W) is PΔV, where P is the atmospheric pressure.
So is ΔU=L-PΔV?
... |
Introduction
I want to simulate a robotic leg that has a closed kinematic chain. The analytical equation i derived are compared with a simulink multibody model.
Initially, my simulation failed, and the inital question was about my formulation of the constraints (which was indeed wrong). I managed to successfully simula... |
In pure rotation, angular momentum is measured about the rotation axis. This angular momentum is measured with respect to that axis. Why do we consider it universal? It should change with respect to other points, e.g. if the reference is taken on the body away from the axis of rotation doesn't the angular momentum chan... |
For example, I have a pendulum as shown in the diagram above. I would like to write down its equation of motion. To do this, I must define a world frame (or inertial frame, or origin).
But this is where I am stuck. I do not understand the thought process behind where I should place it.
After some Googling, I found tha... |
Wavelength of matter wave is given by de-broglie as h/p. I want to know wavelength of what wave is being discussed, or specifically what is matter wave? Is it the 'group wave' that has same velocity as the particle or it is the phase wave. But i know that different phase waves have different wavelengths so they probaba... |
Other than experimental facts that antimatter gravitates the same as matter does, is there theoretically a reason why antiparticles can't create repulsive gravity?
|
I'm a math student, and I'm studying about inverse problems in specific reconstruction of PET images, but I have a problem understanding some things. Some sinograms have black diagonal lines, after searching I found that this are called diamond shaped gaps, but I'm not sure what is the source of these lines.
I believ... |
Why does Simple pendulum's motion not hold as SHM for large angles, only for small angle approximations? The restoring force is still directed towards the mean position. I know mathematically the reason is because at large angles it is not linearly proportional to displacement, but how do I make sense of it intuitively... |
What is the definition of chiral bosons? Until now I only knew the derivation of the chiral fermions (used in the Dirac field equation).
|
Take Wick Rotatability being as the way defined in the article by Helleland:
Wick rotations and real GIT
Is the Gödel universe Wick rotatable according to this definition?
|
In Padmanabhan's Quantum Field Theory, The Why, What and How, in chapter $3$, section $3.1.6$, in the paragraph between equations ($3.75$) and ($3.76$), he states regarding the Belinfante tensor that:
On the other hand, we can easily determine$^{28}$ the energy momentum tensor by introducing a $g^{ab}$ in to the elect... |
I have understood the direction of normal reaction , but I'm confused whether it may result from a pull also or it results only from a push?
|
When the medium of the wave changes, the velocity and the wavelength does change, but not frequency, why?
|
I am currently working on an RC car project and I am trying to find the rolling resistance of the vehicle. I am using the equation:
$T = V_s R_r/ \omega $
,where $T$ is driving torque, $R_r$ is rolling resistance, $V_s$ is linear speed, and $\omega$ is rotational speed. I have an experimental setup that will give me $V... |
I'm working with the paraxial wave equation $$2ik_0\frac{\partial u}{\partial z}+\frac{\partial^2u}{\partial x^2}+\frac{\partial^2u}{\partial y^2}=0,\,-\infty<x<\infty,\,-\infty<y<\infty,\,z\geq 0,$$ where $k_0=\omega/c$, is the wave vector, with $\omega$ and $c$ being the monochromatic wave frequency and the speed of ... |
I'm trying to connect to different pictures used when talking about phonon dispersion relations in metals. Both can be found in standard textbooks, for example Ashcroft & Mermin.
In the first, one starts with the Born Oppenheimer approximation, which says that ions move in an effective potential provided by the electro... |
The expansion of space drains energy from particles. That's why the CMBR contains less energy nowadays than in the early stages of the universe. What does this mean for the neutrinos present in the neutrino background radiation? How fast (or slow) do they travel?
|
We are familiar with the heat capacities $ C_P,C_V $; compressibilities $ \beta_T,\beta_S $; and thermal expansion coefficient $ \alpha_P $:
$ C_P = T \left( \frac{\partial S}{\partial T} \right)_{P},\;
C_V = T \left( \frac{\partial S}{\partial T} \right)_{V},\;
\beta_T = -\frac{1}{V} \left( \frac{\partial V}{\part... |
Why doesn't the shape of the chamber in a thermodynamic machine/heat engine influence the efficency?
Wouldn't a bell / parabola / cone shaped chamber help turn brownian motion into mechanical work of the piston?
Sorry if this question is not precise
|
let $P$ be a point particle of mass $m$ simultaneously subjected to elastic force $ \overrightarrow{F_1}= -k \overrightarrow{e_r}$ and the Newtonian $ \overrightarrow{F_2}= -\frac{\gamma}{r^2}$ with $ k,\gamma >0$ constants and $r = |P-O|$ with $O$ centre of the motion and $ \overrightarrow{e_r} = \overrightarrow{ \... |
Consider an ideal spring which is fixed to the ground (frictionless) at one end, and has a block (of mass $m$, say) attached to it at the other end. When the spring is in its natural length, the block is given a velocity perpendicular to the spring. After this, what would happen?
(This is supposed to be top-down view.... |
Given a square drum with sides length equal to $L$, the squared raised frequencies are
$(\pi m/L)^2 + (\pi n/L)^2 $ with $m,n \in \mathbb{N}^*$.
Here we have four boundary conditions (no vibration on the sides).
Suppose that we have only 3 such conditions, what about the spectrum?
We could also have a drum broken on t... |
The following problem is given (from PHYSICS For Scientists and Engineers with Modern Physics - text book):
"A home run is hit in such a way that the baseball just clears a wall 21 m high, located 130 m from home plate. The ball is hit at an angle of 35° to the horizontal, and air resistance is negligible. Find the ini... |
At Srednicki after eq. (4.10), we have a discussion about that the time ordering operation. Have to be frame inv. I.e it has to be LI.
He wrote that for timelike separation we don't have to worry about the frame dependent of the time ordering.
But, for spacelike separation, we have to take the Hamiltonian to be commuti... |
I am trying to generate an audio signal that, like white noise, has "equal intensity at different frequencies, giving it a constant power spectral density", but unlike white noise, can be expressed without any random character and in a representative way even when just maximally brief burst.
What is the energy distribu... |
Assume a setup where you know the radius $R$ of a conductive loop that has $N$ windings, which is rotating at a frequency of $\omega$. Suppose you also know its length and resistance. Then, you could calculate the inductive voltage through Lenz's Law, and calculate the current through $I = U/R$. Now, I want to calculat... |
It’s a trignometry question where a point is located at height $h$ above a lake, and it’s angle of elevation from a point P located 60 m above surface of lake is 30 and angle of depression of the reflection of the point from point P is 60 degrees. You have to find the distance between point and lake surface. I think th... |
Consider the motion of a billiard ball on two different billiard boards. One board is frictionless and another is not. The magnitude of the friction force of board on the ball is proportional to the speed of the ball. The force is directed opposite to the velocity of the ball.
"The motion of the billiard ball on the fr... |
Consider a Hilbert space of dimension $p$ where $p$ is a prime number. Quantum Fourier transform (QFT) in this space is defined as
$$
|j\rangle \rightarrow \frac{1}{\sqrt{p}} \sum_{k=0}^{p-1}e^{\frac{2\pi i j k}{p}} |k\rangle.
$$ How to construct a quantum circuit that performs this transformation? The standard circui... |
Consider the following two nuclear decay modes:
$$^{64}_{29}\mathrm{Cu} \to e^- + \bar{\nu}_e + ^{64}_{30}\mathrm{Zn} $$
$$^{64}_{29}\mathrm{Cu} \to e^+ + \nu_e + ^{64}_{28}\mathrm{Ni}$$
The solutions I'm given calculate $Q$ using the mass excess of each nuclei. For the first decay mode (measuring mass in keV):
$$Q=\De... |
Recently wile solving questions on Thermal Expansion I encountered two types of questions
Type 1: A rod with one half of mass 'm' and the other of mass '2m' is kept on a horizontal smooth surface, it is heated and it expands longitudinally.
In this question centre of mass of system(the whole rod) remains same at the in... |
In the concept of wave modulation, I'm having trouble to understand why carrier wave cannot transfer information. My assumption is that the reason for that is due to the fact that the frequency, amplitude, and phase of that wave is constant we cannot identify change in the signal (i.e transfer it to $1$'s and $0$'s). B... |
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