(redirected from index of refraction)
Also found in: Dictionary, Thesaurus, Medical, Legal, Acronyms, Encyclopedia, Wikipedia.


Statistical composite that measures changes in the economy or in financial markets, often expressed in percentage changes from a base year or from the previous month. Indexes measure the ups and downs of stock, bond, and some commodities markets, in terms of market prices and weighting of companies in the index.


A statistical measure of the value of a certain portfolio of securities. The portfolio may be for a certain class of security, a certain industry, or may include the most important securities in a given market, among other options. The value of an index increases when the aggregate value of the underlying securities increases, and decreases when the aggregate value decreases. An index may track stocks, bonds, mutual funds, and any other security or investment vehicle, including other indices. An index's value may be weighted; for example, securities with higher prices or greater market capitalization may affect the index's value more than others. One of the most prominent examples of an index is the Dow Jones Industrial Average, which is weighted for price and tracks 30 stocks important in American markets.


The relative value of a variable in comparison with itself on a different date. Many security price indicators such as the Standard & Poor's series and the New York Stock Exchange series are constructed as indexes. Also called stock index. See also base period.


To adjust a variable by a selected measure of relative value. For example, it has been proposed that an investor's basis on a security be indexed for changes in consumer prices so that only real increases in value will be taxed. Also called tax indexing. See also subindex.


An index reports changes up or down, usually expressed as points and as a percentage, in a specific financial market, in a number of related markets, or in an economy as a whole.

Each index -- and there are a large number of them -- measures the market or economy it tracks from a specific starting point. That point might be as recent as the previous day or many years in the past.

For those reasons, indexes are often used as performance benchmarks against which to measure the return of investments that resemble those tracked by the index.

A market index may be calculated arithmetically or geometrically. That's one reason two indexes tracking similar markets may report different results. Further, some indexes are weighted and others are not.

Weighting means giving more significance to some elements in the index than to others. For example, a market capitalization weighted index is more influenced by price changes in the stock of its largest companies than by price changes in the stock of its smaller companies.


(1) A statistical indicator that measures changes in the economy in general or in particular areas.An example is the cost-of-living index.(2) A reference point against which measurements are taken for purposes of making future adjustments.An adjustable-rate mortgage might begin with an interest rate of 6 percent and provide that it will increase or decrease in a like percentage as the increase or decrease between today's quoted price for 10-year U.S.Treasury bonds and the price on the loan's annual anniversary date.We would say that 10-year T-bonds are the index.

Some leading loan indices include

• Wall Street Journal prime
• Federal discount rate
• Fed funds rate
• 11th District Cost of Funds
• 10-year Treasuries
• One-year LIBOR

References in periodicals archive ?
To increase the sensitivity of the experiment, the index of refraction was increased from 1.
For fitting below 500 nm, it was necessary to introduce a wavelength dependent index of refraction as described in paper #1.
In this publication the term total reflectometer is consistently used for all refractometers which are based on the measurement of the critical angle of total reflection for the determination of the index of refraction.
The extremely high index of refraction of calcite that causes the easily-seen double refraction is also responsible for the interference colors (pastel rainbow colors), and are easily seen having small fractures.
These coatings and mirrors, which consist of novel organic-inorganic hybrid materials, will provide improved heat and light management due to their excellent near-IR (NIR)/IR reflectivity, high transparency in the UV-Visible regime, and their tunable index of refraction (n).
The storage mechanism uses charges excited by light and then trapped in the photorefractive medium which modulates the index of refraction by the electro-optic effect to create the storage hologram.
For any solvent, a simple test to tell whether it is as - advertised is to measure the index of refraction, since that number is unique for a given substance.
The geodesic equation becomes non-inertial forces as a result of the variation in the local index of refraction and motion the tetrad field represents.
Propagation in and scattering from a matched metamaterial having a zero index of refraction," Phys.
The imaginary component of the microsphere index of refraction was parameterized using three mixed Gaussian-Lorentz (GL) functions given in Eq.
1D PCs can be dielectric with negative index of refraction in which optical properties change in one direction, while in two other directions, the structure is uniform [6].
This study had not attracted much attention until the fabrication of artificial materials that possess negative index of refraction was experimentally demonstrated by Shelby et al.

Full browser ?