An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A notation convention in → tensor analysis whereby whenever there is an expression with a repeated → index, the summation is done over that index from 1 to 3 (or from 1 to n, where n is the space dimension). For example, the dot product of vectors a and b is usually written as: a.b = Σ (i = 1 to 3) a_i.b_i. In the Einstein notation this is simply written as a.b = a_i.b_i. This notation makes operations much easier. Same as Einstein summation convention.

→ Einstein; → notation.

Representation of numbers, quantities, or other entities by symbols; a system of symbols for such a purpose.

From L. notationem (nom. notatio) "a marking, explanation," from notatus, p.p. of notare "to note."

Namâdgân, from namâd, → symbol, + -gân suffix denoting order, organization, multiplicity.

A mathematical notation system in which the → numerals get different values depending on their position relative to the other numerals. Same as → positional notation and → positional number system.

→ place; → value; → notation.

A system of representing → numbers in which the → position of a → digit in a string of digits affects its value. The decimal system is a positional notation for expressing numbers. Same as → place-value notation and → positional number system.

→ positional; → notation.

A compact format for writing very large or very small numbers. Numbers are made up of three parts: the coefficient, the base and the exponent. For example 3.58 x 10⁴ is the scientific notation for 35,800.

→ scientific; → notation.