How to Numerically Solve a Complex Multiple Integral in Physics?

In summary, the conversation discusses a bidimensional system of N particles with a pair-interaction hamiltonian that includes kinetic and potential energy. The speaker wants to solve a multiple integral involving this hamiltonian, which also depends on positions and momentums. They are open to a numerical solution using software such as SAGE, Mathematica, Matlab, or Python with scipy. Resources for numerical integration using these software are provided.
  • #1
Korbid
17
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For a bidimensional system of N particles, the hamiltonian of pair-interaction is:
[tex]H(\vec{q}_1,\vec{q}_2;\vec{p}_1,\vec{p}_2)=K(\vec{p}_1,\vec{p}_2)+U(\vec{q}_1,\vec{q}_2;\vec{p}_1,\vec{p}_2)[/tex]
where K is the kinetic (translational) energy and U is the potential energy
i want to solve this multiple integral:
[tex]\int\int\int\int{e^{-\frac{H(\vec{q}_1,\vec{q}_2;\vec{p}_1,\vec{p}_2)}{{k_BT}}}}d\vec{q}_1d\vec{q}_2d\vec{p}_1d\vec{p}_2[/tex]
But the pair-potential depends on positions, and momentums as well:
[tex]U=\frac{k}{\tau}e^{\tau/\tau_0}[/tex]
where τ0 and κ are parameters and [tex]τ=τ(\vec{q}_{12};\vec{p}_{12})[/tex]
is a function that depends on relative positions and relative momentums.
how could i solve this horrible integral? i don't need an analytical solution, a numerical solution with any software like SAGE or Mathematica is fine.
 
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  • #2

FAQ: How to Numerically Solve a Complex Multiple Integral in Physics?

How do I approach solving a multiple integral?

The first step in solving a multiple integral is to identify the variables and limits of integration. Then, you can choose to solve the integral using either the iterative method or the change of variables method. The iterative method involves solving each integral one at a time, while the change of variables method involves substituting new variables to simplify the integral.

What is the purpose of multiple integration?

Multiple integration is used to calculate the volume, surface area, and other properties of complex 3D shapes. It is also used in many areas of science, such as physics, chemistry, and engineering, to model and solve problems involving multiple variables.

How do I know which method to use when solving a multiple integral?

The choice of method depends on the complexity of the integral and personal preference. If the integral involves simple functions and limits, the iterative method may be more efficient. However, if the integral is complex and involves trigonometric or exponential functions, the change of variables method may be more useful.

What are some common mistakes to avoid when solving a multiple integral?

Some common mistakes when solving a multiple integral include forgetting to change the limits of integration when using the change of variables method, mixing up the order of integration, and not simplifying the integral before integrating. It is important to carefully follow the steps and check your work to avoid these errors.

Can I use a calculator or computer to solve a multiple integral?

Yes, calculators and computers can be used to solve multiple integrals. However, it is important to understand the concepts behind the integral and the steps involved in solving it. Additionally, it is always a good idea to check the result obtained from a calculator or computer with your own work to ensure accuracy.

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