Sigma (disambiguation)
Encyclopedia
Sigma
is a letter of the Greek alphabet.
Sigma may also refer to:
Sigma
Sigma is the eighteenth letter of the Greek alphabet, and carries the 'S' sound. In the system of Greek numerals it has a value of 200. When used at the end of a word, and the word is not all upper case, the final form is used, e.g...
is a letter of the Greek alphabet.
Sigma may also refer to:
Companies
- Sigma TVSigma TVSigma TV is a commercial network in Cyprus that commenced broadcasting on April 3, 1995. It is a private service and is currently the second-rated channel in Cyprus. Sigma TV is geared at a younger audience, with the focus on the 18-45 age group. It broadcasts a mix of original programmes as...
, a television channel in Cyprus - Sigma Company, an Australian pharmaceutical company
- Sigma CorporationSigma Corporationis a Japanese company founded in 1961, manufacturing cameras, lenses, flashes and other photographic accessories. All Sigma products are produced in the company's own Aizu factory in Bandai, Fukushima, Japan...
, a Japanese camera and lens manufacturer - Sigma Company Limited, a Hungarian debt management company
- Sigma-AldrichSigma-AldrichSigma-Aldrich Corporation , is a life science and high technology company with over 7,600 employees and operations in 40 countries. Its chemical and biochemical products and kits are used in scientific research, biotechnology, pharmaceutical development, the diagnosis of disease, and as key...
, an American chemical company - Sigma DesignsSigma DesignsSigma Designs is an American public corporation that designs and builds high-performance system-on-a-chip semiconductor technologies for Internet-based set-top boxes, DVD players/recorders, high-definition televisions, media processors, digital media adapters, portable media players and home...
, Inc., a US semiconductor manufacturer - SIGMA (verification service)SIGMA (verification service)SIGMA is an electronic verification service offered by Nielsen Media Research and is generally used for commercials, infomercials, video news releases, public service announcements, satellite media tours, and electronic press kits...
, Nielsen Media Research's tracking system for videos - Sigma SportSigma SportSigma Sport is a manufacturer of electronic sports equipment such as the Rox and Topline product lines of heart rate monitors, altimeters, and bike computers....
, a German manufacturer of electronic sports equipment - Sigma ABSigma ABSigma AB is a Swedish consultancy and IT company. The Sigma Group is divided into two business areas: IT & Management, and Information Logistics....
, Swedish IT consultancy company - TelkomsigmaTelkomsigmaPT Sigma Cipta Caraka or telkomsigma , or just Sigma, is an Indonesian-based information and communications technology business solution provider. Telkomsigma is a wholly owned subsidiary of Telkom Indonesia through its investment subsidiary Multimedia Nusantara, and parts of the Telkom Group...
or Sigma Cipta Caraka, an Indonesian ICT business solution provider
Mathematics
- SummationSummationSummation is the operation of adding a sequence of numbers; the result is their sum or total. If numbers are added sequentially from left to right, any intermediate result is a partial sum, prefix sum, or running total of the summation. The numbers to be summed may be integers, rational numbers,...
operator forming a series in mathematics Σ - Standard deviationStandard deviationStandard deviation is a widely used measure of variability or diversity used in statistics and probability theory. It shows how much variation or "dispersion" there is from the average...
in statistics σ - Divisor functionDivisor functionIn mathematics, and specifically in number theory, a divisor function is an arithmetical function related to the divisors of an integer. When referred to as the divisor function, it counts the number of divisors of an integer. It appears in a number of remarkable identities, including relationships...
in number theory σ - Sigma-algebraSigma-algebraIn mathematics, a σ-algebra is a technical concept for a collection of sets satisfying certain properties. The main use of σ-algebras is in the definition of measures; specifically, the collection of sets over which a measure is defined is a σ-algebra...
(σ-algebra, σ-field) in set theory - A busy beaverBusy beaverIn computability theory, a busy beaver is a Turing machine that attains the maximum "operational busyness" among all the Turing machines in a certain class...
function in computability theory Σ -
or 
, sets in the analytical hierarchyAnalytical hierarchyIn mathematical logic and descriptive set theory, the analytical hierarchy is a higher type analogue of the arithmetical hierarchy. It thus continues the classification of sets by the formulas that define them.-The analytical hierarchy of formulas:... -
, a set in the polynomial hierarchyPolynomial hierarchyIn computational complexity theory, the polynomial hierarchy is a hierarchy of complexity classes that generalize the classes P, NP and co-NP to oracle machines... - Harish-Chandra's σ function
- Weierstrass sigma functionWeierstrass sigma functionIn mathematics, the Weierstrass functions are special functions of a complex variable that are auxiliary to the Weierstrass elliptic function. They are named for Karl Weierstrass.-Weierstrass sigma-function:...
Science
- Stefan-Boltzmann constantStefan-Boltzmann constantThe Stefan–Boltzmann constant , a physical constant denoted by the Greek letter σ, is the constant of proportionality in the Stefan–Boltzmann law: the total energy radiated per unit surface area of a black body in unit time is proportional to the fourth power of the thermodynamic temperature.The...
of radiation in physics σ - Sigma factorSigma factorA sigma factor is a bacterial transcription initiation factor that enables specific binding of RNA polymerase to gene promoters. Different sigma factors are activated in response to different environmental conditions...
of RNA polymerase in biology σ - In the Hammett equationHammett equationThe Hammett equation in organic chemistry describes a linear free-energy relationship relating reaction rates and equilibrium constants for many reactions involving benzoic acid derivatives with meta- and para-substituents to each other with just two parameters: a substituent constant and a...
, the electronic substituent constant σ for activation of substituted arenes - Sigma baryonSigma baryonThe Sigma baryons are a family of subatomic hadron particles which have a +2, +1 or -1 elementary charge or are neutral. They are baryons containing three quarks: two up and/or down quarks, and one third quark, which can be either a strange , a charm , a bottom or a top quark...
, a class of baryons in particle physics - Pauli matricesPauli matricesThe Pauli matrices are a set of three 2 × 2 complex matrices which are Hermitian and unitary. Usually indicated by the Greek letter "sigma" , they are occasionally denoted with a "tau" when used in connection with isospin symmetries...
in quantum physics - Cross sectionCross section (physics)A cross section is the effective area which governs the probability of some scattering or absorption event. Together with particle density and path length, it can be used to predict the total scattering probability via the Beer-Lambert law....
σ in physics - Sigma bondSigma bondIn chemistry, sigma bonds are the strongest type of covalent chemical bond. They are formed by head-on overlapping between atomic orbitals. Sigma bonding is most clearly defined for diatomic molecules using the language and tools of symmetry groups. In this formal approach, a σ-bond is...
in chemistry σ - Sigma receptorSigma receptorThe sigma receptors σ1 and σ2 bind to ligands such as 4-PPBP, SA 4503, ditolylguanidine, dimethyltryptamine and siramesine.- Classification :...
, a subtype of opioid receptor - Electrical conductivity, a measure of a material's ability to conduct electricity σ
- Stress (mechanics), the force per unit area applied by internal forces of a material σ
Products
- Sigma (sailplane)Sigma (sailplane)-External links:*...
- Mitsubishi Sigma (disambiguation)
- GM Sigma platformGM Sigma platformSigma is General Motors' mid-size rear-wheel drive automobile platform. The architecture debuted in 2002 with the 2003 Cadillac CTS and is adaptable for all-wheel drive and extended wheelbase versions...
, a mid-size car automobile platform from General Motors Corporation - Smith & Wesson SigmaSmith & Wesson SigmaThe Sigma is Smith & Wesson's venture into using synthetic materials in gun construction, using high-strength polymer material for the frame.Created in 1994, it also incorporates a self-cocking or double-action only firing mechanism, so that the pistol can be fired without delay or preparation...
, a firearm - Sigma GuitarsSigma GuitarsGuitar maker Martin, based in Pennsylvania, created a line of inexpensive guitars in 1970 to compete with the increasing number of imported guitars from Japan and elsewhere...
- The SDS Sigma series of computers from Scientific Data Systems
Video games
- Sigma (Mega Man X), the main villain in the Mega Man X video game series
- Ninja Gaiden SigmaNinja Gaiden SigmaNinja Gaiden Sigma, also known as Ninja Gaiden Σ, is an action-adventure game developed by Team Ninja for the PlayStation 3 video game console. Originally released on Xbox in 2004, it is an enhanced port of Ninja Gaiden and a continuation of a 1988 video game originally released for the Nintendo...
, a PlayStation 3 title in the Ninja Gaiden video game series - Sigma, a character in the BioShock 2BioShock 2BioShock 2 is a first-person shooter video game developed by 2K Marin for Microsoft Windows, PlayStation 3 and Xbox 360. The sequel to the 2007 video game BioShock, it was released worldwide on February 9, 2010....
downloadable content pack "Minerva's Den" - Sigma HarmonicsSigma Harmonicsis a console role-playing game developed and produced by Square Enix for the Nintendo DS handheld game console.-Gameplay:The game is played using the Nintendo DS system's "book" orientation...
, a video game
Other
- Sigma (couch)Sigma (couch)The Ancient Roman furniture, sigma was a semi-circular couch sometimes used at banquets instead of the triclinium. Its name comes from the lunate sigma — which resembles, but which is not at all related to, the Latin letter C and was used in Eastern forms of Greek writing and in the Middle Ages....
, an ancient Roman couch used for banquets - Sigma, CapizSigma, CapizSigma is a 4th class municipality in the province of Capiz, Philippines. According to the 2000 census, it has a population of 27,366 people in 5,541 households.-Barangays:Sigma is politically subdivided into 21 barangays.* Acbo* Amaga* Balucuan...
, a municipality in the Philippines - The Six SigmaSix SigmaSix Sigma is a business management strategy originally developed by Motorola, USA in 1986. , it is widely used in many sectors of industry.Six Sigma seeks to improve the quality of process outputs by identifying and removing the causes of defects and minimizing variability in manufacturing and...
quality management program - OodOodThe Ood are a fictional alien species with telepathic abilities from the long running science fiction series Doctor Who. In the series' narrative, they live in the distant future ....
Sigma, a fictional character from the Doctor Who series - SK Sigma OlomoucSK Sigma OlomoucSK Sigma Olomouc is a Czech football club from the city of Olomouc. They reached the quarterfinals of the 1991-1992 UEFA Cup.Since 2011, Olomouc have had an agreement where FK SAN-JV Šumperk is acting as their farm team.- Historical names :...
, Czech association football team - Space City SigmaSpace City SigmaSpace City Sigma is an Indian science fiction television series that aired on the DD National channel in the late 1980s. It is considered to be the first science fiction series produced in India.-External links:***...
, a 1980s Indian science fiction TV series