CMSC660
CMSC660 I
Math
648
MATH 648 B
AMSC 661
AMSC 614
AMSC 698
PDE by Lawrence C. Evans
``In the theory of communications, it is appropriate to represent an oscillatory signal as the
superposition of elementary wavelets pocessing both a well-defined frequency and a localization
in time. Indeed, the pertinent information is often carried simultaneously by the frequency
emitted and by the temporal structure of the signal--- the example of music is
characteristic. The representation of a signal as a function of time does not bring out the
frequencies in play, whereas on the other hand, the Fourier representation conceals the moment
of emission and the duration of each of the components of the signal. An adequate representation
ought to combine the advantages of the two complementary descriptions; it ought also to be in a
discrete form, which is better suited to the theory of communications".
--- R.Balian, Un principe d'incertitude fort en theorie du signal ou en
mecanique. C.R.Acad.Sci.Paris, 292, Serie II, 1981, 1357-1361.
--- quoted in Y. Meyer "Wavelets and Operators", 1990
``The discovery that quantum physics allows
fundamentally new modes of information
processing has required the existing
theories of computation, information and
cryptography to be superseded by their
quantum generalisations. The Centre for
Quantum Computation, part of the
University of Oxford, conducts theoretical
and experimental research into all aspects
of quantum information processing, and
into the implications of the quantum
theory of computation for physics itself''
--- The Centre for Quantum Computation,
University of Oxford