Felix Hausdorff was a German mathematician who is considered to be the father of modern topology. He introduced the concept of a topological space and developed many of the basic concepts of topology.

Albert Einstein was a German-born theoretical physicist who developed the theory of relativity, one of the two pillars of modern physics. His work is also known for its influence on the philosophy of science.

John von Neumann was a Hungarian-American mathematician who made significant contributions to the theory of games, computer science, and quantum mechanics. He is considered to be one of the most important mathematicians of the 20th century.

Bernhard Riemann was a German mathematician who is known for his work on the Riemann hypothesis, one of the most important unsolved problems in mathematics. He also made significant contributions to the fields of complex analysis, differential geometry, and number theory.

Benoit Mandelbrot was a French-American mathematician who is known for his work on the theory of fractals. He is credited with coining the term 'fractal' and developing the Mandelbrot set, a complex fractal that exhibits a remarkable degree of self-similarity.

Saunders Mac Lane was an American mathematician who is known for his work on the theory of categories, a branch of mathematics that studies the structure of mathematical objects and the relationships between them. He is considered to be one of the founders of category theory.

John Conway was a British mathematician who is known for his work on the theory of knots, a branch of mathematics that studies the properties of knots and other closed curves in three-dimensional space. He is also known for his work on number theory, game theory, and recreational mathematics.

Henri Poincaré was a French mathematician who is known for his work on the theory of dynamical systems, a branch of mathematics that studies the behavior of systems that evolve over time. He is also known for his work on celestial mechanics, number theory, and topology.

Alexander Grothendieck was a French mathematician who is known for his work on the theory of algebraic geometry, a branch of mathematics that studies the geometry of algebraic varieties. He is considered to be one of the most important mathematicians of the 20th century.

Sergei Sobolev was a Russian mathematician who is known for his work on the theory of partial differential equations, a branch of mathematics that studies the behavior of functions that depend on several variables. He is also known for his work on functional analysis and approximation theory.

Andrei Kolmogorov was a Russian mathematician who is known for his work on the theory of probability, a branch of mathematics that studies the likelihood of events. He is also known for his work on measure theory, ergodic theory, and information theory.

Ronald Fisher was a British statistician who is known for his work on the theory of statistics, a branch of mathematics that studies the collection, analysis, interpretation, and presentation of data. He is also known for his work on experimental design and analysis of variance.

Alan Turing was a British mathematician and computer scientist who is known for his work on the theory of computation, a branch of mathematics that studies the limits of what can be computed. He is also known for his work on artificial intelligence, cryptography, and mathematical logic.

Claude Shannon was an American mathematician and engineer who is known for his work on the theory of information, a branch of mathematics that studies the transmission and storage of information. He is also known for his work on cryptography, computer science, and game theory.

George Dantzig was an American mathematician who is known for his work on the theory of optimization, a branch of mathematics that studies the best way to allocate resources. He is also known for his work on linear programming, a technique for solving optimization problems.