• Thumbnail for Quantum mechanics
    as the time-evolution operator, and has the crucial property that it is unitary. This time evolution is deterministic in the sense that – given an initial...
    98 KB (12,084 words) - 11:03, 1 August 2024
  • Thumbnail for Schrödinger equation
    {U}}(t)=e^{-i{\hat {H}}t/\hbar }} is known as the time-evolution operator, and it is unitary: it preserves the inner product between vectors in the Hilbert space. Unitarity...
    74 KB (10,232 words) - 09:07, 10 August 2024
  • Thumbnail for France
    include the mathematician and physicist Henri Poincaré; physicists Henri Becquerel, Pierre and Marie Curie, who remain famous for their work on radioactivity;...
    274 KB (24,704 words) - 05:13, 18 September 2024
  • value is an extended real number (that is in [0, ∞]) and this is clearly a unitary invariant of S. Remark. It is indeed possible that H(S) = +∞ for some density...
    8 KB (1,323 words) - 15:48, 14 September 2024
  • Thumbnail for Environmental issues in Russia
    low-level waste is no more than four giga-becquerels per tonne of alpha activity or twelve giga-becquerels per tonne of gamma-beta activity. An example...
    20 KB (1,989 words) - 01:49, 8 June 2024
  • X-rays in experiments with electron beams in plasma. 1896 – Antoine Henri Becquerel accidentally discovers radioactivity while investigating the work of Wilhelm...
    81 KB (9,961 words) - 12:56, 4 August 2024
  • Thumbnail for Freeman Dyson
    recognized the formula as the pair correlation function of the Gaussian unitary ensemble, which physicists have studied extensively. This suggested that...
    84 KB (8,602 words) - 22:52, 17 September 2024