- Double torus
In mathematics, a double torus is a topological object formed by the
connected sumof two torii. That is to say, from each of two torii the interior of a disk is removed, and the boundaries of the two disks are identified (glued together), forming a double torus.
This is the simplest case of the connected sum of "n" torii. A connected sum of torii is an example of a
two dimensionalmanifold. According to the classification theorem for 2-manifolds, every compact connected 2-manifold is either a sphere, a connected sum of torii, or a connected sum of projective planes. Double torus knots are studied in knot theory.
Bolza surfaceis the most symmetric hyperbolic surface of genus2.
* James R. Munkres, "Topology, Second Edition", Prentice-Hall, 2000, ISBN 0-13-181629-2.
* William S. Massey, "Algebraic Topology: An Introduction", Harbrace, 1967.
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