All articles starting with M
36,687 articles
Multiplication algorithm
A multiplication algorithm is a procedure for computing the product of two numbers or polynomials, from schoolbook long multiplication up to Karatsuba's and FFT-based methods approaching O(n log n).
Multiplication sign
The multiplication sign (×), also called the times sign, is a mathematical symbol for multiplication shaped as a diagonal cross, introduced by William Oughtred in 1631 and standard in elementary arithmetic.
Multiplication table
A multiplication table, also known as a times table, is a table showing the products of pairs of numbers, typically up to 10 or 12.
Multiplicative function
A multiplicative function is an arithmetic function on the positive integers with f(ab) = f(a)f(b) whenever gcd(a, b) = 1; examples include Euler's totient and the Möbius function.
Multiplicative group of integers modulo n
The multiplicative group of integers modulo n, also written Z n, is the finite abelian group of residue classes coprime to n, with order given by Euler's totient function.
Multiplicative inverse
A multiplicative inverse of a, written a⁻¹, is an element that multiplies a to give 1; for ordinary nonzero numbers it is the reciprocal, 1/a, and zero has none.
Multiplicative noise
Multiplicative noise is random forcing whose amplitude depends on the state of the system it perturbs, unlike additive noise, which has a constant amplitude. It appears in stochastic differential and partial differential equations.
Multiplicative order
The multiplicative order of an integer a modulo n is the smallest positive k with a^k ≡ 1 (mod n); it always divides Euler's totient φ(n).
Multiplicity (film)
Multiplicity is a 1996 American science fiction comedy directed by Harold Ramis. It stars Michael Keaton as an executive who is cloned, resulting in four duplicates with distinct personalities.
Multiplier–accelerator model
The multiplier–accelerator model is a family of business-cycle models in which the Keynesian multiplier and the acceleration principle interact, generating cyclical fluctuations without external shocks.
Multipolar neuron
Multipolar neuron: a neuron with one axon and two or more dendrites; Cajal's third structural type, the most common CNS neuron, including pyramidal, Purkinje, and motor neurons.
Multipole expansion
The multipole expansion is a series representation of the potential or field of a localized charge or current source, valid outside the source region, with monopole, dipole, quadrupole, and higher terms.
Multipole radiation
Multipole radiation is electromagnetic or gravitational radiation whose angular structure is described by a multipole expansion, ordered by l, that begins with the lowest moment conservation laws allow.
Multiprocessing
Multiprocessing is the use of two or more processing units within a single computer system, or of multiple cooperating processes, so work proceeds in parallel, contrasting with multithreading.
Multiprotocol Label Switching
Multiprotocol Label Switching (MPLS), also known as tag switching, is a packet-forwarding technique standardized by the IETF in 2001 that routes packets using short labels instead of long address lookups.
Multiproxy analysis
Multiproxy analysis is a paleoclimate method that combines independent proxies, such as tree rings, pollen, and isotopes, to reconstruct past temperature as a single curve with quantified uncertainty.
Multiracial Americans
Multiracial Americans, also called the Two or More Races population, are people reporting more than one race in U.S. census data; counted at 33.8 million (10.2%) in 2020 versus 9 million in 2010, with estimates varying sharply by question format.
Multiracial people
Multiracial people are those of more than one racial ancestry or identity. Coverage spans US census history (one-drop rule, 2000 multiple-race option), the disputed 2020 count of 33.8 million, Brazil's pardo category, and measurement reliability problems.
Multireference configuration interaction
Multireference configuration interaction (MRCI) is a quantum chemistry method that expands the wavefunction over multiple reference configurations with single and double excitations, used for bond breaking, transition metals, and excited states.
Multiresolution analysis
Multiresolution analysis (MRA) is a framework in wavelet and harmonic analysis that decomposes a signal into coarse approximations plus detail components at successively finer scales.
Multirole combat aircraft
A multirole combat aircraft, also called a multirole fighter, is a combat aircraft able to perform both air-to-air and air-to-surface missions, such as ISR and strike.
Multiscale geographically weighted regression
Multiscale geographically weighted regression (MGWR) is a spatial statistics method, introduced by A. Stewart Fotheringham and colleagues in 2017, that extends geographically weighted regression by giving each predictor variable its own spatial bandwidth.
Multiscale modeling and simulation
Multiscale modeling and simulation is a computational approach that couples models at different scales, such as QM/MM and the quasicontinuum method, balancing accuracy and efficiency.
Multiscale topology optimization
Multiscale topology optimization is a computational structural design method that optimizes material layout at two length scales at once, producing a structure and its functionally graded microstructure.
Multiset
A multiset, also called a bag, is a mathematical collection in which elements may appear more than once, each carrying a multiplicity, unlike an ordinary set where repeats collapse.
MultiSETS trial
MultiSETS (Multicenter Schroth Exercise Trial for Scoliosis, NCT01610908) is a University of Alberta randomized trial of Schroth exercises added to standard care in 124 adolescents with idiopathic scoliosis, showing reduced torso asymmetry versus standard care alone.
Multislice method
The multislice method is a numerical technique in electron microscopy that simulates electron scattering by dividing a specimen into thin slices, introduced by Cowley and Moodie in 1957.
Multispectral imaging
Multispectral imaging records a scene in a small number of discrete wavelength bands, between RGB and hyperspectral imaging, used in satellite remote sensing, agriculture, and cultural heritage imaging.
Multispectral optoacoustic tomography
Multispectral optoacoustic tomography (MSOT) is an imaging method that illuminates tissue with multiple laser wavelengths and detects ultrasound, separating hemoglobin, oxygenation, and contrast agents by their absorption spectra.
Multistable mechanical metamaterials
Multistable mechanical metamaterials are engineered structures with two or more stable configurations that switch reversibly under stimuli, enabling vibration isolation, energy absorption, and soft robotics.