Computational physics

Computational physics

Numerical analysis · Simulation Data analysis · Visualization Fluid dynamics Finite element · Riemann solver Smoothed particle hydrodynamics Monte Carlo methods Integration · Gibbs sampling · Metropolis algorithm Particle N-body · Particle-in-cell Molecular dynamics Scientists von Neumann · Godunov

This box: view • talk • edit

Computational physics is the study and implementation of numerical algorithms to solve problems in physics for which a quantitative theory already exists. It is often regarded as a subdiscipline of theoretical physics but some consider it an intermediate branch between theoretical and experimental physics.

Physicists often have a very precise mathematical theory describing how a system will behave. Unfortunately, it is often the case that solving the theory's equations ab initio in order to produce a useful prediction is not practical. This is especially true with quantum mechanics, where only a handful of simple models have complete analytic solutions. In cases where the systems only have numerical solutions, computational methods are used.

Applications of computational physics

Computation now represents an essential component of modern research in accelerator physics, astrophysics, fluid mechanics, lattice field theory/lattice gauge theory (especially lattice quantum chromodynamics), plasma physics (see plasma modeling) and solid state physics. Computational solid state physics, for example, uses density functional theory to calculate properties of solids, a method similar to that used by chemists to study molecules.

Many other more general numerical problems fall loosely under the domain of computational physics, although they could easily be considered pure mathematics or part of any number of applied areas. These include

• Solving differential equations
• Evaluating integrals
• Stochastic methods, especially Monte Carlo methods
• Specialized partial differential equation methods, for example the finite difference method and the finite element method
• The matrix eigenvalue problem – the problem of finding eigenvalues of very large matrices, and their corresponding eigenvectors (eigenstates in quantum physics)
• The pseudo-spectral method

All these methods (and several others) are used to calculate physical properties of the modeled systems. Computational Physics also encompasses the tuning of the software/hardware structure to solve the problems (as the problems usually can be very large, in processing power need or in memory requests).

See also

• Molecular dynamics
• Computational fluid dynamics
• Computational Magnetohydrodynamics
• DCOMP Division of Computational Physics of the American Physical Society
• Important publications in computational physics
• Computational Science
• Mathematical physics
• Open Source Physics, computational physics libraries and pedagogical tools
• Plasma modeling

External links

• APS DCOMP
• SciDAC: Scientific Discovery through Advanced Computing
• Open Source Physics
• SCINET Scientific Software Framework

Additional info - part 2

Computational Magnetohydrodynamics

Computational magnetohydrodynamics (CMHD) is a rapidly developing branch of magnetohydrodynamics that uses numerical methods and algorithms to solve and analyze problems that involve electrically conducting fluids. Most of the methods used in CMHD are borrowed from the well established techniques employed in Computational fluid dynamics. The complexity mainly arises due to the presence of a magnetic field and its coupling with the fluid. One of the important issues is to numerically maintain the (conservation of magnetic flux) condition, from Maxwell's equations, to avoid any unphysical effects.

Computer simulation

A computer simulation, a computer model, or a computational model is a computer program, or network of computers, that attempts to simulate an abstract model of a particular system. Computer simulations have become a useful part of mathematical modeling of many natural systems in physics (computational physics), astrophysics, chemistry and biology, human systems in economics, psychology, and social science and in the process of engineering new technology, to gain insight into the operation of those. ^[1]

DCOMP

DCOMP is the Division of Computational Physics of the American Physical Society (APS). The division has more than 2000 members and the objective of the division is the advancement and dissemination of knowledge regarding the use of computers in physics research and education. This includes, among other areas, their application to experiments, theory, and education as well as the application of physics to the development of computer technology. The Division sprovides to its members, and to all APS members, an opportunity for coordination and a forum for discussion and communication. In addition, the Division promotes research and development in computational physics; enhances prestige and professional standing of its members; encourages scholarly publication; and promotes international cooperation in these activities.

Data analysis

Data analysis is a process of inspecting, cleaning, transforming, and modelling data with the goal of highlighting useful information, suggesting conclusions, and supporting decision making. Data analysis has multiple facets and approaches, encompassing diverse techniques under a variety of names, in different business, science, and social science domains.

Density functional theory

Density functional theory (DFT) is a quantum mechanical theory used in physics and chemistry to investigate the electronic structure (principally the ground state) of many-body systems, in particular atoms, molecules, and the condensed phases. With this theory, the properties of a many-electron system can be determined by using functionals, i.e. functions of another function, which in this case is the spatially dependent electron density. Hence the name density functional theory comes from the use of functionals of the electron density. DFT is among the most popular and versatile methods available in condensed-matter physics, computational physics, and computational chemistry.