An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 12 Search : operator
annihilation operator
  آپارگر ِ نابودی   
âpârgar-e nâbudi

Fr.: opérateur d'annihilation   

In → quantum field theory, the operator that lowers → eigenstates one → energy level, contrarily to the → creation operator.

annihilation; → operator.

creation operator
  آپارگر ِ آفرینش   
âpârgar-e âfarineš

Fr.: opérateur de création   

An operator that acts on the → eigenstate describing the → harmonic oscillator to raise its → energy level by one step. The creation operator is the → Hermitian conjugate operator of the → annihilation operator.

creation; → operator.

d'Alembertian operator
  آپارگر ِ دالامبر   
âpârgar-e d'Alembert

Fr.: d'alembertien   

A second order, → partial differential operator in space-time, defined as: ▫2 = ∂2/∂x2 + ∂2/∂y2 + ∂2/∂z2 - (1/c2)∂2/∂t2, or ▫2 = ∇2 - (1/c2)(∂2/∂t2), where ∇2 is the → Laplacian and c is the → speed of light. This operator is the square of the → four-dimensional operator  ▫, which is Lorentz invariant.

d'Alembert's principle; → operator.

del operator
  آپارگر ِ دل   
âpârgar-e del

Fr.: opérateur del   

In → vector calculus, a vector → partial derivative represented by the symbol → nabla and defined in three dimensions to be:
∇ = (∂/∂x)i + (∂/∂y)j + (∂/∂z)k.
It appears in the operations → gradient: ∇f, → divergence: ∇ . E, → curl: ∇ x E, and → Laplacian: ∇ . ∇f = ∇2f.

From Gk. alphabet letter delta.

four-dimensional operator
  آپارگر ِ چهار-وامونی   
âpârgar-e cahâr-vâmuni

Fr.: opérateur à quatre dimensions   

An operator defined as: ▫ = (∂/∂x, ∂/∂y, ∂/∂z, 1/(jc∂/∂t).

four; → dimensional; → operator.

Hamiltonian operator
  آپارگر ِ هامیلتون   
âpârgar-e Hamilton

Fr.: opérateur hamiltonien   

The dynamical operator in → quantum mechanics that corresponds to the → Hamiltonian function in classical mechanics.

Hamiltonian function; → operator.

Hermitian operator
  آپارگر ِ اِرمیتی   
âpârgar-e Hermiti

Fr.: opérateur hermitien   

An operator A that satisfies the relation A = A*, where A* is the adjoint of A. → Hermitian conjugate.

Hermitian conjugate; → operator.

identity operator
  آپارگر ِ ایدانی   
âpârgar-e idâni

Fr.: opérateur d'identité   

An operator which takes a real number to the same real number.

identity; → operator.

integral operator
  آپارگر ِ دُرُستالی   
âpârgar-e dorostâli

Fr.: opérateur intégral   

Math.: An operator whose inverse is a differential operator.

integral; → operator.

Laplace operator
  آپارگر ِ لاپلاس   
âpârgar-e Laplace

Fr.: opérateur de Laplace   

Same as → Laplacian.

Laplace; → operator.

operator
  آپارگر   
âpârgar

Fr.: opérateur   

Math.: Something that acts on another function to produce another function. In linear algebra an "operator" is a linear operator. In calculus an "operator" may be a differential operator, to perform ordinary differentiation, or an integral operator, to perform ordinary integration.

From → operate; + → -or.

quantum-mechanical operator
  آپارگر ِ مکانیک ِ کو‌آنتومی   
âpârgar-e mekânik-e kuântomi

Fr.: opérateur en mécanique quantique   

A linear → Hermitian operator associated with a physical quantity.

quantum; → mechanics; → operator.