Computational physics

Computer physics , also Computational Physics (CP) or computer-aided physics , is a branch of physics that deals with the computer simulation of physical processes. It is sometimes also called physics informatics or numerical physics .

The methods of numerical mathematics serve as the basis . Computer physics deals with methods that solve the initial equations that describe a physical system numerically or algebraically with the computer or with the simulation of control systems, which makes the establishment of equations unnecessary. Due to comparable processes, there is a close relationship with computational chemistry , which means that they influence one another very strongly.

Working method

Computer-aided physics examines physical problems that can usually be described with equations, but the solution of which cannot be calculated directly in a closed formula. Such closed solutions only exist for very few idealized systems (e.g. Kepler problem , hydrogen atom or two-dimensional Ising model ).

Every simulation is based on a model that describes reality within the framework of certain approximations . The computer is used to implement the modeled system and to measure physical quantities and to determine the effects of the model parameters. Computer-aided physics may also include the adaptation of software and hardware to the problem to be solved.

The spectrum of computing resources required ranges from a few milliseconds on simple PCs to monthly bills on mainframes and supercomputers .

Examples

application areas

Computer-aided physics is now used for research in almost all areas of physics:

• Quantum field theory / lattice theory , e.g. B. in lattice chromodynamics to research the strong interaction
• Astrophysics and cosmology , e.g. B. in the creation of the universe
• Numerical fluid mechanics , e.g. B. in simulations of air resistance
• Statistical Physics , e.g. B. in the Ising or XY model
• Plasma physics
• Solid state physics , e.g. B. at phase transitions
• Thermodynamics , e.g. B. Systems of Condensed Matter
• Meteorology and climatology , e.g. B. in weather and climate simulations
• Biophysics , e.g. B. in the simulation of protein folds

Problem types

Many computer simulations of physical systems can be traced back to the solution of the following mathematical problems:

• Solution of differential equations
• Solution of eigenvalue and eigenvector problems
• Matrix inversion
• Calculation of integrals

Methods

The most common methods of computational physics include:

• Monte Carlo simulation , e.g. B. by means of the Metropolis algorithm
• Molecular dynamics simulation
• Finite difference method
• Finite element method
• Finite volume method
• Spectral method
• Density functional theory

See also

• Cheminformatics
• Bioinformatics
• Computational Engineering Science

literature

• Paul L. DeVries: Computational Physics : Fundamentals Methods Exercises . Spektrum Akad. Verl., Heidelberg, Berlin, Oxford 1995, ISBN 3-86025-336-0 (432 pages).
• Stefan Gerlach: Computer Physics: Introduction, Examples and Applications . 2nd Edition. Springer Spektrum, Berlin, Heidelberg 2019, ISBN 978-3-662-59245-8 (290 pages).
• Alexander K. Hartmann, Heiko Rieger, Optimization Algorithms in Physics , Wiley-VCH, 2002, ISBN 3527403078
• Alexander K. Hartmann, A Practical Guide To Computer Simulation , World Scientific Publishing Company, 2009, ISBN 9812834141
• István Montvay , Gernot Münster, Quantum Fields on a Lattice , Cambridge Monographs on Mathematical Physics, ISBN 0521599172
• Tao Pang, An Introduction to Computational Physics , Cambridge University Press, 2006, ISBN 0521825695
• Philipp OJ Scherer, Computational Physics: Simulation of Classical and Quantum Systems, second edition , Springer, Berlin, 2013, ISBN 9783319004006
• Franz J. Vesely, Computational Physics - An Introduction , Kluwer Academic / Plenum Publishers, New York-London 2001, ISBN 0306466317
• Harald Wiedemann: Numerical Physics. Selected examples of theoretical physics with C ++ . 2nd Edition. Springer Spectrum, Berlin 2019, ISBN 978-3-662-58185-8 .

Web links

• Franz Vesely: "Computational Physics" web tutorial
• Link catalog on the topic of computer-aided physics at curlie.org (formerly DMOZ )