940 research outputs found
Neutron Acceleration in Uniform Electromagnetic Fields
The question as to whether neutron acceleration can occur in uniform
electromagnetic fields is examined. Although such an effect has been predicted
using the canonical equations of motion some doubt has been raised recently as
to whether it is in principle observable for a spin 1/2 particle. To resolve
this issue a gedanken experiment is proposed and analyzed using a wave packet
construction for the neutron beam. By allowing arbitrary orientation for the
neutron spin as well as for the electric and magnetic fields a non vanishing
acceleration of the center of the neutron wave packet is found which confirms
the predictions of the canonical formalism.Comment: 11 page
On the Relation Between Quantum Mechanical and Classical Parallel Transport
We explain how the kind of ``parallel transport'' of a wavefunction used in
discussing the Berry or Geometrical phase induces the conventional parallel
transport of certain real vectors. These real vectors are associated with
operators whose commutators yield diagonal operators; or in Lie algebras those
operators whose commutators are in the (diagonal) Cartan subalgebra.Comment: 3 pages, no figure
Classical and Quantum Interaction of the Dipole
A unified and fully relativistic treatment of the interaction of the electric
and magnetic dipole moments of a particle with the electromagnetic field is
given. New forces on the particle due to the combined effect of electric and
magnetic dipoles are obtained. Four new experiments are proposed, three of
which would observe topological phase shifts.Comment: 10 pages, Latex/Revtex. Some minor errors have been correcte
Gravitational Phase Operator and Cosmic Strings
A quantum equivalence principle is formulated by means of a gravitational
phase operator which is an element of the Poincare group. This is applied to
the spinning cosmic string which suggests that it may (but not necessarily)
contain gravitational torsion. A new exact solution of the Einstein-
Cartan-Sciama-Kibble equations for the gravitational field with torsion is
obtained everywhere for a cosmic string with uniform energy density, spin
density and flux. A novel effect due to the quantized gravitational field of
the cosmic string on the wave function of a particle outside the string is used
to argue that spacetime points are not meaningful in quantum gravity.Comment: 22 pages, to be published Phys. Rev. D. Some minor changes have been
made and a reference has been added to the paper of D.V. Gal'tsov and P.S.
Letelier, Phys. Rev. D 47 (1993) 4273, which first contained the metric (2.2)
external to the cosmic string. The present paper extends this solution to a
regular solution inside the string as wel
Towards a quantum Hall effect for atoms using electric fields
An atomic analogue of Landau quantization based on the Aharonov-Casher (AC)
interaction is developed. The effect provides a first step towards an atomic
quantum Hall system using electric fields, which may be realized in a
Bose-Einstein condensate
Quantum Interference to Measure Spacetime Curvature: A Proposed Experiment at the Intersection of Quantum Mechanics and General Relativity
An experiment in Low Earth Orbit (LEO) is proposed to measure components of
the Riemann curvature tensor using atom interferometry. We show that the
difference in the quantum phase of an atom that can travel along
two intersecting geodesics is given by times the spacetime
volume contained within the geodesics. Our expression for also
holds for gravitational waves in the long wavelength limit.Comment: 7 pages LaTeXed with RevTeX 4.0, 2 figures. Submitted to the 2003
Gravity Research Foundation Essay Contes
Axiomatic Holonomy Maps and Generalized Yang-Mills Moduli Space
This article is a follow-up of ``Holonomy and Path Structures in General
Relativity and Yang-Mills Theory" by Barrett, J. W. (Int.J.Theor.Phys., vol.30,
No.9, 1991). Its main goal is to provide an alternative proof of this part of
the reconstruction theorem which concerns the existence of a connection. A
construction of connection 1-form is presented. The formula expressing the
local coefficients of connection in terms of the holonomy map is obtained as an
immediate consequence of that construction. Thus the derived formula coincides
with that used in "On Loop Space Formulation of Gauge Theories" by Chan, H.-M.,
Scharbach, P. and Tsou S.T. (Ann.Phys., vol.167, 454-472, 1986). The
reconstruction and representation theorems form a generalization of the fact
that the pointed configuration space of the classical Yang-Mills theory is
equivalent to the set of all holonomy maps. The point of this generalization is
that there is a one-to-one correspondence not only between the holonomy maps
and the orbits in the space of connections, but also between all maps from the
loop space on to group fulfilling some axioms and all possible
equivalence classes of bundles with connection, where the equivalence
relation is defined by bundle isomorphism in a natural way.Comment: amslatex, 7 pages, no figure
Action principle formulation for motion of extended bodies in General Relativity
We present an action principle formulation for the study of motion of an
extended body in General Relativity in the limit of weak gravitational field.
This gives the classical equations of motion for multipole moments of arbitrary
order coupling to the gravitational field. In particular, a new force due to
the octupole moment is obtained. The action also yields the gravitationally
induced phase shifts in quantum interference experiments due to the coupling of
all multipole moments.Comment: Revised version derives Octupole moment force. Some clarifications
and a reference added. To appear in Phys. Rev.
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