Content deleted Content added
→The demon algorithm: semantic list |
move tag up |
||
| (2 intermediate revisions by 2 users not shown) | |||
Line 1:
{{no footnotes|date=January 2011}}▼
The '''demon algorithm''' is a [[Monte Carlo method]] for efficiently sampling members of a [[microcanonical ensemble]] with a given energy. An additional degree of freedom, called 'the demon', is added to the system and is able to store and provide energy. If a drawn microscopic state has lower energy than the original state, the excess energy is transferred to the demon. For a sampled state that has higher energy than desired, the demon provides the missing energy if it is available. The demon can not have negative energy and it does not interact with the particles beyond exchanging energy. Note that the additional degree of freedom of the demon does not alter a system with many particles significantly on a macroscopic level.
In [[thermodynamical system]]s, equal macroscopic properties (e. g. temperature) can result from different microscopic properties (e. g. velocities of individual particles). Computer simulations of the full equations of motion for every individual particle to simulate microscopic properties is computationally very expensive. [[Monte Carlo methods]] can overcome this problem by sampling microscopic states according to stochastic rules instead of modeling the complete microphysics.
Line 22:
* [[Monte Carlo methods]]
* [[Metropolis algorithm]] to sample microscopic states at a fixed temperature
▲{{no footnotes|date=January 2011}}
== References ==
Line 29 ⟶ 27:
* {{cite book
| author = Harvey Gould and Jan Tobochnik and Wolfgang Christian
| title = An Introduction to Computer Simulation Methods: Applications to Physical Systems
| publisher = Addison Wesley
| year = 2006
| isbn = 978-0-8053-7758-3
| chapter= Chapter 15: Monte Carlo Simulations of Thermal Systems
| edition = 3rd
}}
* {{cite journal
| |||