127,136 research outputs found
An approach to nonstandard quantum mechanics
We use nonstandard analysis to formulate quantum mechanics in
hyperfinite-dimensional spaces. Self-adjoint operators on
hyperfinite-dimensional spaces have complete eigensets, and bound states and
continuum states of a Hamiltonian can thus be treated on an equal footing. We
show that the formalism extends the standard formulation of quantum mechanics.
To this end we develop the Loeb-function calculus in nonstandard hulls. The
idea is to perform calculations in a hyperfinite-dimensional space, but to
interpret expectation values in the corresponding nonstandard hull. We further
apply the framework to non-relativistic quantum scattering theory. For
time-dependent scattering theory, we identify the starting time and the
finishing time of a scattering experiment, and we obtain a natural separation
of time scales on which the preparation process, the interaction process, and
the detection process take place. For time-independent scattering theory, we
derive rigorously explicit formulas for the M{\o}ller wave operators and the
S-Matrix
But we had hoped ... : The Road We\u27ve Traveled; the Road that Lies Ahead
(Excerpt)
It is a privilege to be here with you at this annual gathering to explore matters of consequence affecting our churches at the beginning of this new millennium. I feel honored to be invited into the ongoing conversation of the Institute of Liturgical Studies. I\u27ve had opportunities to cross paths with many in this Lutheran family through associations at the Liturgical Conference, the North American Academy of Liturgy, and Notre Dame, and all have been positive and enriching experiences. My contacts have served to deepen my appreciation of the strong commitment of the Lutheran churches to promoting life-giving worship within congregations. I am inspired by the desire for unity that runs deep in the Lutheran soul
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