All Questions
Tagged with algorithms computational-physics
60
questions
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Force-simulation for graph layout: How to avoid particle collapsing into a single point?
In a force-based graph-layout simulation using Barnes-Hut, what are the conditions for collapse? With collapse I mean multiple (or even all) nodes "collapsing" into a single point.
Is there ...
- 1
1
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22
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Any quantum Monte-Carlo algorithm for calculating the lowest eigenenergy in each symmetry sector?
Suppose we have a hamiltonian which has the parity symmetry (e.g., the Heisenberg model with the open boundary condition). Is there any quantum Monte-Carlo algorithm which can be used to calculate the ...
- 1,957
2
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54
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Is there a proof for critical slow-down in Monte Carlo?
It is physically understood why the standard Metropolis-Hasting algorithm slows down near the critical temperature, since it doesn’t utilize the divergence of the correlation length. However, I’m ...
- 2,123
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37
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Is Quantum State Tomography (QST) an inherently supervised or unsupervised problem in Machine Learning?
I am studying how to apply neural networks to the problem of Quantum State Tomography (QST) and I got confused when it comes to decide if this is a supervised or unsupervised learning problem.
At ...
- 161
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51
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Understanding chapter 3.1 (Laplace's equation) in Introduction to electrodynamics Griffiths 4 ed [duplicate]
I really need help to understand chapter 3.1.
What is the method of relaxation?
How can I use the method of relaxation to solve Laplace's equation?
How can I use the first and second uniqueness ...
- 9
1
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77
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Simplest quantum Monte-Carlo method for the Bose-Hubbard model
I want to use quantum Monte-Carlo results to benchmark an algorithm for the Bose-Hubbard model. There are so many QMC methods in the market, so which one is the simplest one? I want the ground state ...
- 1,957
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61
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How are the boundary conditions given in the SIMPLE algorithm on a forward staggered grid for a lid driven cavity flow?
I have a code given by my professor in which he applies the boundary conditions for the lid driven cavity flow. All the enforcement of boundary conditions I have seen elsewhere completely differ from ...
- 11
2
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1
answer
121
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Numerically computing induced magnetic field from current density
Let's say we have current density $J_i$ on a discretized grid with $(N_x \times N_y \times N_z)$ points. What is the best procedure to compute the induced magnetic field $(B_i)$ from the current ...
- 23
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119
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What are the advantages of tensor network algorithms over monte-carlo simulations in terms of time-evolution?
I understand that tensor networks and monte carlo simulations are based on completely different principles. However, to my knowledge both are used to simulate the time evolution of a system. Is there ...
- 193
1
vote
1
answer
39
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An example problem to solve using 100 qubits?
Suppose we have in our possession 100 pairs of electrons.
Each electron A1 - A100 is entangled with its respective twin B1 - B100. Each entangled electron pair has been set up to have opposite spins (...
- 593
3
votes
1
answer
144
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Grover's algorithm & using wave interference for computing
Grover's quantum search algorithm contends that it is possible to search for a specific item in an N-sized unsorted database in only $\sqrt N$ attempts. Classically, it takes N/2 attempts on average ...
- 593
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votes
1
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99
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Sensor Array Position Calibration in Anisotropic Media
Problem.
I have a sensor array consisting of $n \gg 4$ receivers at unknown locations $\langle x_n, y_n, z_n\rangle$ embedded in an anisotropic medium whose index of refraction varies as a known ...
- 799
1
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113
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Why are time-reversible integration algorithms in molecular dynamics simulations favorable?
I read that integration algorithms that are not time-reversible tend to be less "stable". Where stable means that the total energy stays constant (is conserved). I'd like to know what it ...
- 481
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82
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Reference request: Numerical techniques, Monte-Carlo (MC), Density Matrix Renormalization Group (DMRG), Dynamical Mean-Field Theory (DMFT)
I am an undergraduate student and my previous learning in physics is more on theory instead of numerics. I would be very grateful if you can point me to good introductory lecture notes/lecture videos ...
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140
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Algorithm for solving Poisson's equation numerically
I need an algorithm to solve Poisson's equation for gravitational potential.
$$ \nabla^2\phi = 4\pi G\rho $$
where, $\phi$ is Gravitational Potential.
I am trying PDE for the first time so, I need ...
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