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Henrik Petrini
Henrik Petrini (15 April 1863 – 6 October 1957) was a Swedish mathematician. His mathematical contributions are mainly connected with the theory of partial differential equations, in particular potential theory. He was born in Falun and received his PhD in 1890 from Uppsala University in mechanics, where he subsequently held a position as professor. In 1901 he moved to Växjö Växjö ( ) is a city and the seat of Växjö Municipality, Kronoberg County, Sweden. It had 70,489 inhabitants (2019) out of a municipal population of 95,995 (2021). It is the administrative, cultural, and industrial centre of Kronoberg County ..., where he worked as a lektor for mathematics and physics at the gymnasium. In 1914 he finally moved to Stockholm. He is best known for his counterexample of a continuous function for which the Newton potential is not twice differentiable. He was also interested in pedagogical and theological questions and was known to the general public for his radical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sweden
Sweden, ; fi, Ruotsi; fit, Ruotti; se, Ruoŧŧa; smj, Svierik; sje, Sverji; sju, Sverje; sma, Sveerje or ; yi, שוועדן, Shvedn; rmu, Svedikko; rmf, Sveittiko. formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic country and the List of European countries by area, fifth-largest country in Europe. The Capital city, capital and largest city is Stockholm. Sweden has a population of 10.5 million, and a low population density of ; around 87% of Swedes reside in urban areas in the central and southern half of the country. Sweden’s urban areas together cover 1.5% of its land area. Because the country is so long, ranging from 55th parallel north, 55°N to 69th parallel north, 69°N, the climate of Sweden is diverse. Sweden has been inhabited since Prehistoric Sweden, prehistoric times, . T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics with the major subdisciplines of number theory, algebra, geometry, and analysis, respectively. There is no general consensus among mathematicians about a common definition for their academic discipline. Most mathematical activity involves the discovery of properties of abstract objects and the use of pure reason to prove them. These objects consist of either abstractions from nature orin modern mathematicsentities that are stipulated to have certain properties, called axioms. A ''proof'' consists of a succession of applications of deductive rules to already established results. These results include previously proved theorems, axioms, andin case of abstraction from naturesome basic properties that are considered true starting poin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uppsala University
Uppsala University ( sv, Uppsala universitet) is a public research university in Uppsala, Sweden. Founded in 1477, it is the oldest university in Sweden and the Nordic countries still in operation. The university rose to significance during the rise of Sweden as a great power at the end of the 16th century and was then given a relative financial stability with a large donation from King Gustavus Adolphus in the early 17th century. Uppsala also has an important historical place in Swedish national culture, identity and for the Swedish establishment: in historiography, literature, politics, and music. Many aspects of Swedish academic culture in general, such as the white student cap, originated in Uppsala. It shares some peculiarities, such as the student nation system, with Lund University and the University of Helsinki. Uppsala belongs to the Coimbra Group of European universities and to the Guild of European Research-Intensive Universities. It has ranked among the wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematical model, models, and mathematics#Calculus and analysis, change. History One of the earliest known mathematicians were Thales of Miletus (c. 624–c.546 BC); he has been hailed as the first true mathematician and the first known individual to whom a mathematical discovery has been attributed. He is credited with the first use of deductive reasoning applied to geometry, by deriving four corollaries to Thales' Theorem. The number of known mathematicians grew when Pythagoras of Samos (c. 582–c. 507 BC) established the Pythagoreans, Pythagorean School, whose doctrine it was that mathematics ruled the universe and whose motto was "All is number". It was the Pythagoreans who coined the term "mathematics", and with whom the study of mathemat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Differential Equation
In mathematics, a partial differential equation (PDE) is an equation which imposes relations between the various partial derivatives of a multivariable function. The function is often thought of as an "unknown" to be solved for, similarly to how is thought of as an unknown number to be solved for in an algebraic equation like . However, it is usually impossible to write down explicit formulas for solutions of partial differential equations. There is, correspondingly, a vast amount of modern mathematical and scientific research on methods to numerically approximate solutions of certain partial differential equations using computers. Partial differential equations also occupy a large sector of pure mathematical research, in which the usual questions are, broadly speaking, on the identification of general qualitative features of solutions of various partial differential equations, such as existence, uniqueness, regularity, and stability. Among the many open questions are the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potential Theory
In mathematics and mathematical physics, potential theory is the study of harmonic functions. The term "potential theory" was coined in 19th-century physics when it was realized that two fundamental forces of nature known at the time, namely gravity and the electrostatic force, could be modeled using functions called the gravitational potential and electrostatic potential, both of which satisfy Poisson's equation—or in the vacuum, Laplace's equation. There is considerable overlap between potential theory and the theory of Poisson's equation to the extent that it is impossible to draw a distinction between these two fields. The difference is more one of emphasis than subject matter and rests on the following distinction: potential theory focuses on the properties of the functions as opposed to the properties of the equation. For example, a result about the singularities of harmonic functions would be said to belong to potential theory whilst a result on how the solution dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Falun
Falun () is a city and the seat of Falun Municipality in Dalarna County, Sweden, with 37,291 inhabitants in 2010. It is also the capital of Dalarna County. Falun forms, together with Borlänge, a metropolitan area with just over 100,000 inhabitants. Falun was originally famous for its copper mine, and is today an important service and industrial city even though the mine is closed (since 1992). Faluån is a river, flowing through the city, separating it into two sides. Falu copper mine is located on one of the sides which during many centuries was one of Sweden's main business. This side of the river was usually called "the mining side", where not many plants grew due to the toxic smoke which contaminated the soil. On the other side of the river, where the smoke did not reach, set many large villas, which made this side to be called "the delightful side". The centre of Falun consists of classical pedestrian streets with small shops. In 1998, the city reclaimed the award of " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanics
Mechanics (from Ancient Greek: μηχανική, ''mēkhanikḗ'', "of machines") is the area of mathematics and physics concerned with the relationships between force, matter, and motion among physical objects. Forces applied to objects result in displacements, or changes of an object's position relative to its environment. Theoretical expositions of this branch of physics has its origins in Ancient Greece, for instance, in the writings of Aristotle and Archimedes (see History of classical mechanics and Timeline of classical mechanics). During the early modern period, scientists such as Galileo, Kepler, Huygens, and Newton laid the foundation for what is now known as classical mechanics. As a branch of classical physics, mechanics deals with bodies that are either at rest or are moving with velocities significantly less than the speed of light. It can also be defined as the physical science that deals with the motion of and forces on bodies not in the quantum rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Växjö
Växjö ( ) is a city and the seat of Växjö Municipality, Kronoberg County, Sweden. It had 70,489 inhabitants (2019) out of a municipal population of 95,995 (2021). It is the administrative, cultural, and industrial centre of Kronoberg County and the episcopal see of the Diocese of Växjö and the location of Växjö Cathedral. The town is home to Linnaeus University. Etymology The city's name is believed to be constructed from the words ("road") and ("lake"), meaning the road over the frozen Växjö Lake that farmers used in the winter to get to the marketplace which later became the city. History In contrast to what was believed a century ago, there is no evidence of a special pre-Christian significance of the site. The pagan cultic center of Värend may have been located at Hov, a nearby village. An episcopal see since the 11thcentury, the city did not get its city charter until 1342, when it was issued by Magnus Eriksson. The cathedral of St Sigfrid dates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stockholm
Stockholm () is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden as well as the List of urban areas in the Nordic countries, largest urban area in the Nordic countries. Approximately 1 million people live in the Stockholm Municipality, municipality, with 1.6 million in the Stockholm urban area, urban area, and 2.4 million in the Metropolitan Stockholm, metropolitan area. The city stretches across fourteen islands where Mälaren, Lake Mälaren flows into the Baltic Sea. Outside the city to the east, and along the coast, is the island chain of the Stockholm archipelago. The area has been settled since the Stone Age, in the 6th millennium BC, and was founded as a city in 1252 by Swedish statesman Birger Jarl. The city serves as the county seat of Stockholm County. Stockholm is the cultural, media, political, and economic centre of Sweden. The Stockholm region alone accounts for over a third of the country's Gross d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newton Potential
In mathematics, the Newtonian potential or Newton potential is an operator in vector calculus that acts as the inverse to the negative Laplacian, on functions that are smooth and decay rapidly enough at infinity. As such, it is a fundamental object of study in potential theory. In its general nature, it is a singular integral operator, defined by convolution with a function having a mathematical singularity at the origin, the Newtonian kernel Γ which is the fundamental solution of the Laplace equation. It is named for Isaac Newton, who first discovered it and proved that it was a harmonic function in the special case of three variables, where it served as the fundamental gravitational potential in Newton's law of universal gravitation. In modern potential theory, the Newtonian potential is instead thought of as an electrostatic potential. The Newtonian potential of a compactly supported integrable function ''f'' is defined as the convolution u(x) = \Gamma * f(x) = \int_ \Gamma(x ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lars Gårding
Lars Gårding (7 March 1919 – 7 July 2014) was a Swedish mathematician. He made notable contributions to the study of partial differential equations and partial differential operators. He was a professor of mathematics at Lund University in Sweden 1952–1984. Together with Marcel Riesz, he was a thesis advisor for Lars Hörmander. Biography Gårding was born in Hedemora, Sweden but grew up in Motala, where his father was an engineer at the plant. He began to study mathematics in Lund in 1937 with the first intention of becoming an actuary. His doctorate thesis, which was written under supervision of Marcel Riesz, was first on group representations in 1944, but in the following years he changed his research focus to the theory of partial differential equations. He held the professorship of mathematics at Lund University , motto = Ad utrumque , mottoeng = Prepared for both , established = , type = Publi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
