翻訳と辞書
Words near each other
・ Transfer mispricing
・ Transfer molding
・ Transfer of equity
・ Transfer of learning
・ Transfer of mitochondrial and chloroplast DNA to the nucleus
・ Transfer of panel paintings
・ Transfer of Power
・ Transfer of Property Act 1882
・ Transfer of sovereignty over Hong Kong
・ Transfer of sovereignty over Macau
・ Transfer of the Portuguese Court to Brazil
・ Transfer of the São Francisco River
・ Transfer of training
・ Transfer of Undertakings (Protection of Employment) Regulations 2006
・ Transfer Office
Transfer operator
・ Transfer orbit
・ Transfer Orbit Stage
・ Transfer paper
・ Transfer payment
・ Transfer payments multiplier
・ Transfer pricing
・ Transfer principle
・ Transfer printing
・ Transfer problem
・ Transfer RNA
・ Transfer RNA-like structures
・ Transfer roller
・ Transfer secret
・ Transfer stamping


Dictionary Lists
翻訳と辞書 辞書検索 [ 開発暫定版 ]
スポンサード リンク

Transfer operator : ウィキペディア英語版
Transfer operator
: ''The transfer operator is different from the transfer homomorphism.''
In mathematics, the transfer operator encodes information about an iterated map and is frequently used to study the behavior of dynamical systems, statistical mechanics, quantum chaos and fractals. The transfer operator is sometimes called the Ruelle operator, after David Ruelle, or the Ruelle–Perron–Frobenius operator in reference to the applicability of the Frobenius–Perron theorem to the determination of the eigenvalues of the operator.
The iterated function to be studied is a map f:X\rightarrow X for an arbitrary set X. The transfer operator is defined as an operator \mathcal acting on the space of functions \ as
:(\mathcal\Phi)(x) = \sum_ g(y) \Phi(y)
where g:X\rightarrow\mathbb is an auxiliary valuation function. When f has a Jacobian determinant, then g is usually taken to be g=1/|J|.
The above definition of the transfer operator can be shown to be the point-set limit of the measure-theoretic pushforward of ''g'': in essence, the transfer operator is the direct image functor in the category of measurable spaces. The left-adjoint of the Frobenius–Perron operator is the Koopman operator or composition operator.
==Applications==
Whereas the iteration of a function f naturally leads to a study of the orbits of points of X under iteration (the study of point dynamics), the transfer operator defines how (smooth) maps evolve under iteration. Thus, transfer operators typically appear in physics problems, such as quantum chaos and statistical mechanics, where attention is focused on the time evolution of smooth functions. In turn, this has medical applications to rational drug design, through the field of molecular dynamics.
It is often the case that the transfer operator is positive, has discrete positive real-valued eigenvalues, with the largest eigenvalue being equal to one. For this reason, the transfer operator is sometimes called the Frobenius–Perron operator.
The eigenfunctions of the transfer operator are usually fractals. When the logarithm of the transfer operator corresponds to a quantum Hamiltonian, the eigenvalues will typically be very closely spaced, and thus even a very narrow and carefully selected ensemble of quantum states will encompass a large number of very different fractal eigenstates with non-zero support over the entire volume. This can be used to explain many results from classical statistical mechanics, including the irreversibility of time and the increase of entropy.
The transfer operator of the Bernoulli map b(x)=2x-\lfloor 2x\rfloor is exactly solvable and is a classic example of deterministic chaos; the discrete eigenvalues correspond to the Bernoulli polynomials. This operator also has a continuous spectrum consisting of the Hurwitz zeta function.
The transfer operator of the Gauss map h(x)=1/x-\lfloor 1/x \rfloor is called the Gauss–Kuzmin–Wirsing (GKW) operator and due to its extraordinary difficulty, has not been fully solved. The theory of the GKW dates back to a hypothesis by Gauss on continued fractions and is closely related to the Riemann zeta function.

抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)
ウィキペディアで「Transfer operator」の詳細全文を読む



スポンサード リンク
翻訳と辞書 : 翻訳のためのインターネットリソース

Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.