42,772 articles
Kolar Gold Fields
Kolar Gold Fields (KGF), also known as the Kolar gold mines, is a gold-mining region in Karnataka, India, worked until 2001 to depths of 3.4 km.
Kolbe electrolysis
Kolbe electrolysis is an organic electrochemical reaction in which carboxylic acids are oxidized at an anode, lose carbon dioxide, and dimerize to form alkanes with doubled carbon chains.
Kolbe nitrile synthesis
The Kolbe nitrile synthesis is an organic reaction that prepares alkyl nitriles by reacting alkyl halides with metal cyanides, extending the carbon chain by one atom.
Kolbe–Schmitt reaction
The Kolbe–Schmitt reaction is an organic carboxylation reaction, reported by Hermann Kolbe in 1860 and improved by Rudolf Schmitt, that converts phenols into salicylic acid, the precursor to aspirin.
Kollur Mine
The Kollur Mine, also known as the Kollur Diamond Mine, was a historic alluvial diamond mine on the Krishna River in Andhra Pradesh, India, active in the seventeenth century.
Kolmogorov complexity
Kolmogorov complexity, also known as algorithmic entropy or program-size complexity, is the length of the shortest program producing a given string, a measure discovered independently by Solomonoff, Kolmogorov, and Chaitin.
Kolmogorov equations
The Kolmogorov equations are the forward and backward differential equations, introduced by Andrei Kolmogorov in 1931, that describe how the transition probabilities of a Markov process change over time.
Kolmogorov extension theorem
The Kolmogorov extension theorem, also called the Daniell–Kolmogorov theorem, is a result in probability theory: consistent finite-dimensional distributions determine a probability measure on the product space.
Kolmogorov–Arnold–Moser theorem
The Kolmogorov–Arnold–Moser theorem, or KAM theorem, states that most invariant tori of an integrable Hamiltonian system survive a small perturbation. Kolmogorov stated it in 1954; Arnold and Moser proved it in the early 1960s.
Kolmogorov–Sinai entropy
Kolmogorov–Sinai entropy, also called metric entropy or measure-theoretic entropy, measures the average rate at which a dynamical system creates information, introduced by Kolmogorov in 1958 and extended by Sinai in 1959.
Kolmogorov–Smirnov test
The Kolmogorov–Smirnov test, or K–S test, is a nonparametric statistical test comparing probability distributions via the largest gap between cumulative distribution functions, proposed by Kolmogorov and Smirnov in the 1930s.
Kolmogorov's inequality
Kolmogorov's inequality, also called Kolmogorov's maximal inequality, is a probability result bounding the chance that any partial sum of independent, zero-mean, finite-variance random variables exceeds a threshold, key to the strong law of large numbers.
Kolmogorov's three-series theorem
Kolmogorov's three-series theorem, also called the three series theorem, gives necessary and sufficient conditions for almost sure convergence of a series of independent random variables.
Kolmogorov's zero–one law
Kolmogorov's zero–one law, also called Kolmogorov's 0-1 law, is a probability theorem stating every tail event of independent random variables has probability 0 or 1.
Komar mass
The Komar mass is a definition of total mass-energy in general relativity, introduced by Arthur Komar in 1959 for stationary spacetimes and equal to the ADM mass there.
Kondo cloud
The Kondo cloud (近藤雲) is the spatial region of conduction electrons that quantum-coherently forms a spin-singlet state screening a magnetic impurity over the Kondo length ξK.
Kondo effect
The Kondo effect is the anomalous rise of resistivity as a metal containing dilute magnetic impurities cools, first observed in 1934 and explained by Jun Kondo in 1964.
Kondo insulator
A Kondo insulator, also known as a Kondo semiconductor or heavy-fermion semiconductor, is a strongly correlated material in which the Kondo effect opens a narrow band gap at low temperature.
Kondo lattice
The Kondo lattice is a condensed matter physics model, introduced in 1977, in which localized magnetic moments couple to conduction electrons and the standard description of heavy-fermion metals.
Kőnig's theorem (graph theory)
Kőnig's theorem, also called the König–Egerváry theorem, states that in every bipartite graph the maximum matching size equals the minimum vertex cover size, first proved by Dénes Kőnig in 1931.
König's theorem (set theory)
König's theorem is a result in cardinal arithmetic stating that if κᵢ < λᵢ for all i, then the sum of the κᵢ is strictly less than the product of the λᵢ.
Konrad Bates Krauskopf
Konrad Bates Krauskopf (1910–2003) was an American geochemist who spent his career at Stanford University, did seminal work on trace metals in seawater, and wrote the textbook Introduction to Geochemistry.
Konrad Bleuler
Konrad Bleuler (1912–1992) was a Swiss physicist and mathematician, professor of theoretical physics at Bonn, known for the Gupta–Bleuler formalism for quantizing the electromagnetic field.
Konrad Tiefenbacher
Konrad Tiefenbacher is an organic chemist, professor at the University of Basel and ETH Zürich since 2016, known for running terpene cyclizations and β-selective glycosylations inside self-assembled molecular capsules.
Konstantin Batygin
Konstantin Batygin, born in Moscow in 1986, is a Caltech professor of planetary science best known for the Planet Nine hypothesis, proposing a distant unseen planet.
Konstantin Novoselov
Konstantin Novoselov, also known as Kostya Novoselov, is a Russian-British physicist who isolated graphene at Manchester in 2004, winning the 2010 Nobel Prize in Physics with Andre Geim.
Konstantin Y. Bliokh
Konstantin Y. Bliokh is a theoretical physicist working on spin–orbit interactions of light and wave momentum, an Ikerbasque Research Professor at the Donostia International Physics Centre since 2024.
Koop Lammertsma
Koop Lammertsma is a Dutch organophosphorus and computational chemist, professor emeritus at the Vrije Universiteit Amsterdam and Distinguished Visiting Professor at the University of Johannesburg, known for low-valent phosphorus chemistry and the 2021 International Arbuzov Prize.
Köppen climate classification
The Köppen climate classification is an empirical system dividing world climates into five major classes and 30 sub-types by temperature and precipitation, designed to align with global vegetation distribution.
Kore
Kore, also designated Jupiter XLIX and provisionally S/2003 J 14, is a small retrograde moon of Jupiter in the Pasiphae group, discovered in 2003 at Mauna Kea and named by the IAU in 2007.