Newest Questions

Interested to calculate TDM of a molecule in the presence of a dielectric. What is the go-to way right now in research circles?

In classical mechanics, the space of states is the cotangent bundle of configuration space. This space of states is also called phase space. In the physical case where phase space represents all ...

I have a question regarding the implementation of constraint equations as delta functions in integrals. My confusion can best be illustrated with a quick example: Consider a Gaussian integral of the ...

Lookin for a way to run quantum circuits with de-polarizing noise via quantum trajectories and not density matrix

Consider an operator like the modular Hamiltonian $K$ defined by $$\rho=e^{-K}$$ where $\rho$ is some (reduced) density matrix. So $K$ depends non-linearly on $\rho$ in general. It can be shown that ...

I've been playing around with Bohmian mechanics in electronic systems. I really like the interpretation of particle trajectories in terms of the continuity, Hamilton Jacobi equation and guiding ...

I am currently taking a course in theoretical (classical) Mechanics, where I have learned about the Darboux theorem. My professor has also mentioned one can "reduce the system by symmetry", ...

I was watching this video on how to derive the Schwarzschild metric when at around 4:30, he mentions that because the Ricci scalar $R$ is zero, there is no immediate change in volume due to the ...

Hi! For the last few weeks i've been trying to figure out the motion equations for the ring in the Jumping Ring experiment, with little to no success. I know the differential equation that would ...

In Section 7.2.1 of Bergman's Fundamentals of Heat and Mass Transfer, there is a derivation of the Blasius equation $$ 2 \frac{d^3 f}{d \eta^3} + f \frac{d^2 f}{d \eta^2} = 0$$ through the definitions ...

Here is what I observed: Background: I kept this bottle in my room, at a place where: half of it was in complete darkness (well, minimal light did fall on it, but very minimal). the other half ...

According to the Lorentz transformations, if an observer $O'$ moves at a relative velocity $\beta$ with respect to another observer $O$, the proper times $t$ and $t'$ would be related by: $$ t=\sqrt{1-...

C14 is created locally and recently, and decays at a fixed half-life much longer than the time taken to be absorbed, so accurate-ish dating by isotope ratio is possible, but dating the Earth with the ...

I want to learn Edwards-Anderson and Sherrington-Kirkpatrick models properly with their calculations (Replica symmetry, phase transition, etc.). I need couple of sources such as books and papers ...

In an attempt to understand the Reeh-Schlieder theorem, I am currently studying this paper, in which Witten provides a discussion using the formalism of quantum field theory. It is quite ...

I was pondering the nature of momentum conservation in non-ideal systems and noticed a beautiful, continuous functional/mathematical chain linking potential energy all the way to momentum. It frames ...

I struggle to understand how theories that are based on renormalization can be considered mathematically rigorous. I understand how renormalization works for non-abelian theories, through loop ...

So, when the gas (initially at the heater temperature T1) is compressed isothermally, it does not come into contact with the cooler, and in order to prevent the gas temperature from exceeding the ...

I'm trying to make sense of how resonances in pipes work. I gather that, in the instance below, the fundamental resonant frequency of the 1m closed pipe (ignoring end correction etc.) is $$ f_{0} = \...

A metal sphere is suspended in water at 0°c by a thread when water is heated to 4°c , what happens to the tension in the thread? I thought that the tension would increase because the water would ...

Imagine C has positive formal charge bonded to three methyl groups (CH3). How do we compute the overlap between sigma bond and empty $p$-orbital? The motivation for this is to show how energy ...

I was thinking how could we model the attempt of hitting a mosquito standing on a wall. The mosquito (a point P) is standing on a wall (a plane) and we are trying to hit it with an object of area A ...

I've heard this statement from a few sources and the reasoning given is something the lones of that the expansion of the universe would have made objects too far and red shifted to observe, and reach. ...

I don't understand why the reverse Carnot Cycle works. Let's consider the isothermal expansion of a gas (body). The gas does work, but its temperature remains constant. For this to happen, the gas ...

While deriving ideal gas equation we assumed the container to be a cuboid and then we took the volume to be $lbh$ where l, b, h are length, breadth, and height respectively. Will the equation still be ...

In classical mechanics we say that a classical particle obeys the equations of motion, whereas in quantum mechanics a particle can take any path, not just the classical one. But when we quantize a ...

Acceleration involves a squared time item, and Newton's law of universal gravitation contains a product of two masses. Such mathematical expressions seem to be meaningless when taken in isolation; ...

Reading Schutz's book on GR: On page 9, there's a derivation that I don't follow. $\newcommand{\d}{\Delta} \newcommand{\b}[1]{\bar{#1}}$ Then in the expression for $\d\b{s}^2$, $$\d\b{s}^2 = -(\d\b{...

I am currently reflecting a bit on the formal structure of the theory presented in Callen's classic text Thermodynamics and an Introduction to Thermostatistics. I was originally going to post a more ...

I'm having trouble understanding how two entangled particles stay correlated once they are measured. As an example, if they are anti-correlated in their spins, and one particle is measured to have a ...