Universal wavefunctionThe universal wavefunction (or wave function), introduced by Hugh Everett in his 1973 PhD thesis The Theory of the Universal Wave Function, informs a core concept in the relative state interpretation or many-worlds interpretation of quantum mechanics. It later received investigation from James Hartle and Stephen Hawking in which they derived a specific solution to the Wheeler–deWitt equation to explain the initial conditions of the Big Bang cosmology.
Quantum key distributionQuantum key distribution (QKD) is a secure communication method that implements a cryptographic protocol involving components of quantum mechanics. It enables two parties to produce a shared random secret key known only to them, which then can be used to encrypt and decrypt messages. The process of quantum key distribution is not to be confused with quantum cryptography, as it is the best-known example of a quantum-cryptographic task.
Piecewise linear manifoldIn mathematics, a piecewise linear (PL) manifold is a topological manifold together with a piecewise linear structure on it. Such a structure can be defined by means of an atlas, such that one can pass from chart to chart in it by piecewise linear functions. This is slightly stronger than the topological notion of a triangulation. An isomorphism of PL manifolds is called a PL homeomorphism.
Particle in a spherically symmetric potentialIn quantum mechanics, a particle in a spherically symmetric potential is a system with a potential that depends only on the distance between the particle and a center. This is how isolated atoms are described, and plays a central role as a first approximation to the formation of chemical bonds. In the general case, the dynamics of a particle in a spherically symmetric potential are governed by a Hamiltonian of the following form: where is the mass of the particle, is the momentum operator, and the potential depends only on , the modulus of the radius vector.
