Physical world and mathematics

Gillespie algorithm

The Gillespie algorithm, also called the stochastic simulation algorithm, is a Monte Carlo method proposed by Daniel T. Gillespie in 1976 for simulating chemical reactions exactly.

Oct 20, 2026

Gilwern Volcanic Formation (GIVO, Gwn): Llanvirn Middle Ordovician unit of the Builth Volcanic Group in the Builth-Llandrindod Inlier, central Wales; basic lapilli tuffs, reworked tuffaceous sandstones, dacite domes, and the Castle Bank Biota.

GIM mechanism

The GIM mechanism, or Glashow-Iliopoulos-Maiani mechanism, is a cancellation in electroweak theory, introduced in 1970, that suppresses flavor-changing neutral currents and quantitatively predicted the charm quark, confirmed in 1974.

Gimbal lock

Gimbal lock is the loss of one degree of freedom in a three-gimbal mechanism when two gimbal axes align, leaving the system unable to rotate about one axis.

Gimel function

The gimel function, named after the Hebrew letter gimel, maps each infinite cardinal κ to κ^cf(κ), where cf(κ) is κ's cofinality, and determines cardinal exponentiation.

Ginger Zee

Ginger Zee, also known as Ginger Renee Colonomos, is an American broadcast meteorologist who joined ABC News in 2011 and became "Good Morning America's" chief meteorologist in 2013.

Gingerol

Gingerol is the pungent phenolic oil of fresh ginger, existing as a series of homologs of which 6-gingerol is the principal form and accounts for ginger's pungent flavor and reported anti-inflammatory, antioxidant, and anticarcinogenic effects.

Gino Fano

Gino Fano (1871–1952) was an Italian mathematician born in Mantua, regarded as the founder of finite geometry and known for the Fano plane and Fano varieties central to modern algebraic geometry.

Ginsenosides

Ginsenosides are triterpenoid saponins, natural glycosidic compounds found nearly exclusively in ginseng plants of the genus Panax, with more than 150 isolated and considered ginseng's main active principles.

Ginzburg–Landau theory

Ginzburg–Landau theory, also called the Landau–Ginzburg model, is a phenomenological theory of superconductivity published in 1950 by Vitaly Ginzburg and Lev Landau that describes superconductors near their critical temperature.

Giorgi Japaridze (გიორგი ჯაფარიძე)

Giorgi Japaridze (გიორგი ჯაფარიძე), also published as Giorgie Dzhaparidze, is a Georgian-born logician and full professor at Villanova University in Pennsylvania, known for creating computability logic and cirquent calculus.

Giorgio Bellettini

Giorgio Bellettini is an Italian experimental particle physicist who helped found the CDF experiment at Fermilab and was co-spokesperson when the top quark was discovered in 1995.

Giorgio Parisi

Giorgio Parisi is an Italian theoretical physicist at Sapienza University of Rome, awarded half of the 2021 Nobel Prize in Physics for work on spin glasses.

Giovanna Barbarella

Giovanna Barbarella is an Italian chemist at the CNR Institute of Organic Synthesis and Photoreactivity in Bologna who introduced oligothiophene S,S-dioxides in 1998 and applied thiophene-based materials to light-emitting devices and fluorescent probes.

Giovanni Amelino-Camelia

Giovanni Amelino-Camelia, born 1965 in Naples, is an Italian quantum-gravity physicist at the University of Naples Federico II who proposed doubly special relativity and helped establish quantum-gravity phenomenology.

Giovanni Battista Rizza

Giovanni Battista Rizza (1924–2018) was an Italian mathematician at the University of Parma who worked on quasi-complex, quasi-Hermitian, and Kähler manifolds; the Rizza manifold is named for him.

Giovanni Frattini

Giovanni Frattini (1852–1925) was an Italian group theorist who taught in Roman schools and is known for the Frattini subgroup and the Frattini argument, which he took from Capelli.

Giovanni Giambelli

Giovanni Giambelli, also known as Giovanni Zeno Giambelli, was an Italian mathematician trained under Corrado Segre in Turin, remembered for the Giambelli determinantal formula in Schubert calculus.

Giovanni Inghirami

Giovanni Inghirami (1779–1851) was an Italian Piarist priest, astronomer, and cartographer who directed Florence's Osservatorio Ximeniano and produced the first geometric map of the Grand Duchy of Tuscany.

Giovanni Jona-Lasinio

Giovanni Jona-Lasinio, born 1932 in Florence, is an Italian theoretical physicist at Sapienza University of Rome known for the Nambu–Jona-Lasinio model of spontaneous symmetry breaking and the Boltzmann Medal.

Giovanni Plana

Giovanni Plana (1781–1864) was an Italian astronomer and mathematician who held the chair of astronomy at the University of Turin. He is noted for his summation formula.

Giovanni Schiaparelli

Giovanni Schiaparelli (1835–1910) was an Italian astronomer and director of the Brera Observatory in Milan whose 1877 Mars observations introduced the canali and Martian nomenclature still in use.

Girsanov theorem

The Girsanov theorem, also called the Cameron–Martin–Girsanov theorem, is a stochastic analysis result stating Brownian motion with drift becomes driftless under an equivalent probability measure.

Girth (graph theory)

In graph theory, the girth of a graph is the length of its shortest cycle in edges; graphs with no cycles are assigned girth 0 or infinity by convention.

Gisbert Schneider

Gisbert Schneider is a Swiss-based biochemist and bioinformatician, Full Professor of Computer-Assisted Drug Design at ETH Zurich since 2010, credited with introducing AI-based drug design and coining "scaffold hopping".

GISP2

GISP2, short for Greenland Ice Sheet Project 2, was a US ice drilling project that recovered a 3053 m core through the full Greenland Ice Sheet in 1993.

GISS-E2

GISS-E2 is a global climate model developed at the NASA Goddard Institute for Space Studies, built on the ModelE atmospheric code, and coupled to alternative ocean models.

GISTEMP

GISTEMP, the GISS Surface Temperature Analysis, is NASA's estimate of global surface temperature change, produced by the Goddard Institute for Space Studies from land and ocean data since 1880.

Giulia Galli

Giulia Galli is a condensed matter physicist known for first-principles simulations of solids and liquids; she is a University of Chicago professor and directs MICCoM at Argonne.