Differential equations |
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Scope |
Classification |
Solution |
People |
Differential equations are prominent in many scientific areas. Nonlinear ones are of particular interest for their commonality in describing real-world systems and how much more difficult they are to solve compared to linear differential equations. This list presents nonlinear ordinary differential equations that have been named, sorted by area of interest.
Name | Order | Equation | Application | Reference |
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Abel's differential equation of the first kind | 1 | Class of differential equation which may be solved implicitly | [1] | |
Abel's differential equation of the second kind | 1 | Class of differential equation which may be solved implicitly | [1] | |
Bernoulli equation | 1 | Class of differential equation which may be solved exactly | [2] | |
Binomial differential equation | Class of differential equation which may sometimes be solved exactly | [3] | ||
Briot-Bouquet Equation | 1 | Class of differential equation which may sometimes be solved exactly | [4] | |
Cherwell-Wright differential equation | 1 | or the related form | An example of a nonlinear delay differential equation; applications in number theory, distribution of primes, and control theory | [5] [6] [7] |
Chrystal's equation | 1 | Generalization of Clairaut's equation with a singular solution | [8] | |
Clairaut's equation | 1 | Particular case of d'Alembert's equation which may be solved exactly | [9] | |
d'Alembert's equation or Lagrange's equation | 1 | May be solved exactly | [10] | |
Darboux equation | 1 | Can be reduced to a Bernoulli differential equation; a general case of the Jacobi equation | [11] | |
Elliptic function | 1 | Equation for which the elliptic functions are solutions | [12] | |
Euler's differential equation | 1 | A separable differential equation | [13] | |
Euler's differential equation | 1 | A differential equation which may be solved with Bessel functions | [13] | |
Jacobi equation | 1 | Special case of the Darboux equation, integrable in closed form | [14] | |
Loewner differential equation | 1 | Important in complex analysis and geometric function theory | [15] | |
Logistic differential equation (sometimes known as the Verhulst model) | 2 | Special case of the Bernoulli differential equation; many applications including in population dynamics | [16] | |
Lorenz attractor | 1 | Chaos theory, dynamical systems, meteorology | [17] | |
Nahm equations | 1 | Differential geometry, gauge theory, mathematical physics, magnetic monopoles | [18] | |
Painlevé I transcendent | 2 | One of fifty classes of differential equation of the form ; the six Painlevé transcendents required new special functions to solve | [19] | |
Painlevé II transcendent | 2 | One of fifty classes of differential equation of the form ; the six Painlevé transcendents required new special functions to solve | [19] | |
Painlevé III transcendent | 2 | One of fifty classes of differential equation of the form ; the six Painlevé transcendents required new special functions to solve | [19] | |
Painlevé IV transcendent | 2 | One of fifty classes of differential equation of the form ; the six Painlevé transcendents required new special functions to solve | [19] | |
Painlevé V transcendent | 2 | One of fifty classes of differential equation of the form ; the six Painlevé transcendents required new special functions to solve | [19] | |
Painlevé VI transcendent | 2 | All of the other Painlevé transcendents are degenerations of the sixth | [19] | |
Rabinovich–Fabrikant equations | 1 | Chaos theory, dynamical systems | [20] | |
Riccati equation | 1 | Class of first order differential equations that is quadratic in the unknown. Can reduce to Bernoulli differential equation or linear differential equation in certain cases | [21] | |
Rössler attractor | 1 | Chaos theory, dynamical systems | [22] |
Name | Order | Equation | Applications | Reference |
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Duffing equation | 2 | Oscillators, hysteresis, chaotic dynamical systems | [46] | |
Lewis regulator | 2 | Oscillators | [47] | |
Liénard equation | 2 | with odd and even | Oscillators, electrical engineering, dynamical systems | [48] |
Rayleigh equation | 2 | Oscillators (especially auto-oscillation), acoustics; the Van der Pol equation is a Rayleigh equation | [49] | |
Van der Pol equation | 2 | Oscillators, electrical engineering, chaotic dynamical systems | [50] |
Name | Order | Equation | Applications | Reference |
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Brusselator | 1 | A type of autocatalytic reaction modelled at constant concentration | [51] | |
Oregonator | 1 | A type of autocatalytic reaction modelled at constant concentration | [52] |
Name | Order | Equation | Applications | Reference |
---|---|---|---|---|
Allee effect | 1 | Population biology | [53] | |
Arditi–Ginzburg equations | 1 | Population dynamics | [54] | |
FitzHugh–Nagumo model or Bonhoeffer-van der Pol model | 1 | Action potentials in neurons, oscillators | [55] | |
Hodgkin-Huxley equations | 1 | Action potentials in neurons | [56] | |
Kuramoto model | 1 | Synchronization, coupled oscillators | [57] | |
Lotka–Volterra equations | 1 | Population dynamics | [58] | |
Price equation | 1 | Evolution and change in allele frequency over time | [59] | |
SIR model | 1 | Epidemiology | [60] |
Name | Order | Equation | Applications | Reference |
---|---|---|---|---|
Bass diffusion model | 1 | A Riccati equation used in marketing to describe product adoption | [61] | |
Ramsey–Cass–Koopmans model | 1 | Neoclassical economics model of economic growth | [62] [63] | |
Solow–Swan model | 1 | Model of long run economic growth | [64] |
Chaos theory is an interdisciplinary area of scientific study and branch of mathematics. It focuses on underlying patterns and deterministic laws of dynamical systems that are highly sensitive to initial conditions. These were once thought to have completely random states of disorder and irregularities. Chaos theory states that within the apparent randomness of chaotic complex systems, there are underlying patterns, interconnection, constant feedback loops, repetition, self-similarity, fractals and self-organization. The butterfly effect, an underlying principle of chaos, describes how a small change in one state of a deterministic nonlinear system can result in large differences in a later state. A metaphor for this behavior is that a butterfly flapping its wings in Brazil can cause a tornado in Texas.
In mathematics, a transcendental number is a real or complex number that is not algebraic – that is, not the root of a non-zero polynomial of finite degree with rational coefficients. The best-known transcendental numbers are π and e. The quality of a number being transcendental is called transcendence.
In mathematics, a series expansion is a technique that expresses a function as an infinite sum, or series, of simpler functions. It is a method for calculating a function that cannot be expressed by just elementary operators.
In mathematics, an operation is a function which takes zero or more input values to a well-defined output value. The number of operands is the arity of the operation.
In mathematics and physics, the Kadomtsev–Petviashvili equation is a partial differential equation to describe nonlinear wave motion. Named after Boris Borisovich Kadomtsev and Vladimir Iosifovich Petviashvili, the KP equation is usually written as
The Lorenz system is a system of ordinary differential equations first studied by mathematician and meteorologist Edward Lorenz. It is notable for having chaotic solutions for certain parameter values and initial conditions. In particular, the Lorenz attractor is a set of chaotic solutions of the Lorenz system. The term "butterfly effect" in popular media may stem from the real-world implications of the Lorenz attractor, namely that several different initial chaotic conditions evolve in phase space in a way that never repeats, so all chaos is unpredictable. This underscores that chaotic systems can be completely deterministic and yet still be inherently unpredictable over long periods of time. Because chaos continually increases in systems, it is impossible to predict the future of systems well. For instance, even the small flap of a butterfly's wings could set the world on a vastly different trajectory, such as by causing a hurricane. The shape of the Lorenz attractor itself, when plotted in phase space, may also be seen to resemble a butterfly.
In mathematics, d'Alembert's equation, sometimes also known as Lagrange's equation, is a first order nonlinear ordinary differential equation, named after the French mathematician Jean le Rond d'Alembert. The equation reads as
In mathematics, the Ernst equation is an integrable non-linear partial differential equation, named after the American physicist Frederick J. Ernst.
In mathematics, a diffiety is a geometrical object which plays the same role in the modern theory of partial differential equations that algebraic varieties play for algebraic equations, that is, to encode the space of solutions in a more conceptual way. The term was coined in 1984 by Alexandre Mikhailovich Vinogradov as portmanteau from differential variety.
In theoretical physics, the logarithmic Schrödinger equation is one of the nonlinear modifications of Schrödinger's equation, first proposed by Gerald H. Rosen in its relativistic version in 1969. It is a classical wave equation with applications to extensions of quantum mechanics, quantum optics, nuclear physics, transport and diffusion phenomena, open quantum systems and information theory, effective quantum gravity and physical vacuum models and theory of superfluidity and Bose–Einstein condensation. It is an example of an integrable model.
The following is a timeline of scientific computing, also known as computational science.
Wiktor Eckhaus was a Polish–Dutch mathematician, known for his work on the field of differential equations. He was Professor Emeritus of Applied Mathematics at the Utrecht University.
Peter John Olver is a British-American mathematician working in differential geometry.
Michael Ghil is an American and European mathematician and physicist, focusing on the climate sciences and their interdisciplinary aspects. He is a founder of theoretical climate dynamics, as well as of advanced data assimilation methodology. He has systematically applied dynamical systems theory to planetary-scale flows, both atmospheric and oceanic. Ghil has used these methods to proceed from simple flows with high temporal regularity and spatial symmetry to the observed flows, with their complex behavior in space and time. His studies of climate variability on many time scales have used a full hierarchy of models, from the simplest ‘toy’ models all the way to atmospheric, oceanic and coupled general circulation models. Recently, Ghil has also worked on modeling and data analysis in population dynamics, macroeconomics, and the climate–economy–biosphere system.
In mathematics, the Simon problems are a series of fifteen questions posed in the year 2000 by Barry Simon, an American mathematical physicist. Inspired by other collections of mathematical problems and open conjectures, such as the famous list by David Hilbert, the Simon problems concern quantum operators. Eight of the problems pertain to anomalous spectral behavior of Schrödinger operators, and five concern operators that incorporate the Coulomb potential.
Alexandre Mikhailovich Vinogradov was a Russian and Italian mathematician. He made important contributions to the areas of differential calculus over commutative algebras, the algebraic theory of differential operators, homological algebra, differential geometry and algebraic topology, mechanics and mathematical physics, the geometrical theory of nonlinear partial differential equations and secondary calculus.
Charles Laurie Dolph was an American mathematician known for his research in applied mathematics and engineering.
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Erich Hans Rothe was a German-born American mathematician, who did research in mathematical analysis, differential equations, integral equations, and mathematical physics. He is known for the Rothe method used for solving evolution equations.