Refereed Conference and Journal Papers of Dr Harvey Cohen in Physics and Geophysics
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PhD
ANU 
Harvey Alan Cohen, Dispersion Theoretic Approach to Graph Theories of Charged Particles of Spin 0, 1/2, 1
, Instute of Advanced Study, Australian National University, May 1965. Chapter 2 A New Approach to Calculations in the Quantum Field Theory of Charged particles opens as follows: The calculations we perform in subsequent chapters comprise the first exposition of quantum electrodynamics that does not involve the concept of renormalisation and yet does not reject graph theory. Two principles guide us: Principle A asserts the validity of the dispersion relations appropriate to the quantities to be calculated, some of these DR being well known, others postulated by us for the first time. This principle is used to help us ascertain the graph elements for new theories as well as providing our basic computational device. Principle B asserts the correctness of the wellknown graph elements for Dirac spin 1/2, scalar spin zero, and 5x5 β spin zero, and prescribes that as much of Lagrangian formalism and DysonWick procedures as seem substantive be utilised to determine the graph elements for previously unconsidered theories.  
Published Papers on Theoretical and Mathematical Physics  

H. A. Cohen,
Covariant Wave Equations for Charged Particles
of Higher Spin in an Arbitrary Gravitational Field,
Il Nuovo Cimento, Serie X, Vol 52A, 1967 pp 12421253
 
H. A. Cohen^{*} and J. Smith^{**},
The CConserving Decay Modes η → π^{0}e^{+}e^{} and
η → π^{0}μ^{+}μ^{}  
H. A. Cohen,
Vacuum polarization in the Lee and Yang theory of charged spin one
,
Il Nuovo Cimento A Series 10
21 Luglio 1968, Volume 56, Issue 2, pp 467478
Summary:
The radiative correction, to ordere 2, to the photon propagator in the Lee and Yang theory of charged spinone bosons, is calculated in a dispersiontheoretic manner.
Some general aspects of the ξlimiting formalism are
discussed. A useful matrix treatment of Lorentz tensors is
presented in an Appendix.
 
A.J. Bracken and H. A. Cohen,
Five Classes of Transformations of Dirac Spinors
� The FreeParticle Dirac Equation Is Brought to �p_{0}, �p_{1}, �p_{2}, �p_{3} and �mLinear� Forms �,
Progress of Theoretical Physics, Vol 26, No 1, 1969, pp 816831.


A.J. Bracken and H. A. Cohen, On Canonical SO(4,1) Transformations of the Dirac Equation, Journal of Mathematical Physics, Vol 10, No 11, Nov. 1969, pp 2024. Abstract: Certain matrix transformations of the freeparticle Dirac equation are described as momentum dependemt SO(4,1) transformations. Such of these belonging to any one of five subgroups G^{(α)}(α=0,1,2,3,4,5) are canonical, preserving the Lorentzinvariant product in a corresponding one of five modes of expression. The Dirac equation itself is linear in all five components p_{α}[p_{μ}(μ=0,1,2,3) is the fourmomentum operator, p_{4}=m ] of the "fivevector" p^{~}, and a transformation in G^{(β)} has the additional property that the component p_{β} appears linearly also in the transformed equation. The Mendlowitz and the FoldyWouthuysenTani accordingly are in G^{(0)}, the SO(4) subgroup; and that proposed by Chakrabarti is in G^{(4)}, the SO(3,1) subgroup associated with homogeneous Lorentz transformations. For any p^{~`} obtained from p^{~} by a momentumdependent Lorentz transformation, there is a corresponding transform of the Dirac equation. Where p_{α} appears in the transformed equation, p_{`α} appears in the transformed equation. The ambiguities which arise in the specification of the transform leading to a given such equation are associated with the existence of a "little group" for any such p^{~`}. 

1971 
H. A. Cohen,
On the Derivation of the PryceFoldyWouthuysen transformation,
American Journal of Physics,
Vol 39, April 1971, pp 409412.


1972 
H. A. Cohen,
On Time NonSpecial Quantum Mechanics, Acta Physica Austrica, Suppl. IX, 1972
pp 851855.


E.F. Carter and H. A. Cohen,
The Classical Problem of Charge and Pole, American Journal of Physics, Vol 41, Issue 8, Aug 1973, pp 944950.


H. A. Cohen, On the Dirac Monopole Potential,
Prog. Theor. Phys. Vol. 50 No. 2 (1973) pp. 691696 

1974 
H. A. Cohen and M.Z. Shaharir The Action Principle
in Quantum Mechanics,
International Journal of Theoretical Physics, Vol. 11 No. 5 (1974) pp. 289303  
H. A. Cohen, Is There a
Quantization Condition for the Classical
Problem of Charge and Pole,
Foundations of Physics, Vol. 4 No. 1 (1974) pp. 115120 
Published Papers on Geophysics and Remote Observation via Satellite .  
1997.1 
E.A. Essex, P. Webb, I. Horvath. and H.A. Cohen, The Use of Microsatellites in Monitoring the Ionosphere/Plasmasphere in Proc. COSPAR Colloquium on Microsatellites as Research Tools, Ed. F.B Hsiao, at National Cheng Hung Uniiversity Tainan, Taiwan, 1517 December, 1997 COSPAR Colloquia Series 10, pp276279 
Writings on Qualitative Physics [3]
H.A. Cohen, The Art of Snaring Dragons, M.I.T. Artificial Intelligence Laboratory Memo Number 338, May 1975.
Dragons are formidable problems. challenging, and yet solvable using little or even no algebra or calculus.
Dragons are also distinguished (unlike other physics problems seen by the tyro as "difficult") by the fact that both the tyro  and the experienced physicist, are confident with their
 sodifferent  predictions. Thus such Dragons are akin to the
Conservation Puzzles of Piaget, where both the fouryear old preconserver,
and the six year conserver are equally confident with their (differing!) conclusions.
In this paper, written when the writer was part of the LOGO Group at the MIT Artificial Intelligence Laboratory,
an explanation is given in terms of the Frames concept of Marvin Minsky.
H.A. Cohen, with illustrations by Jeni Rawson, A Dragon Hunter"s Box, Hanging Lake Books, Melbourne, 1974. { A componendium of qualitative problems in dynamics }
H.A. Cohen, Mathematical Dragon Hunting on the La Trobe Campus,
Australian ViceChancellor"s Committee (AVCC) Educational Newsletter, 3/73, January 1974.
To stimulate the intellectual growth
of students a new style of student exercise, the
Dragon, has been devised and utilised in a course
in applied mathematics at La Trobe University.
Publications Since 89 By Year
This is a collection of papers in image engineering and visual information systems,
including image processing generally including numberplate recognition
and speedup issues, image restoration, (IFS and) fractal image coding, issues in image retrieval
using thumbnails, and parallel processing techniques, together with some papers
devoted to the design of image codecs, to aspects of satellite systems and to the education of engineers.
Publications Prior to 89 By Topic excluding Physics Papers
These papers are grouped by topic. Topic titles include qualitative physics, mathematics education,
OZNAKI  a pioneering educational robotics project, the La Trobe Talking Communicator ( developed for
severely disable nonspeech students ).
Papers on Physics and Geophysics
This directory of papers in theoretical particle physics and quantum electrodynamics includes the abstracts
for each paper.
Primers on VIS and Image Engineering
VIS = Visual Information Systems.Topics: Edges. Interesting points. Image restoration.
Image access via thumbnails.
Texture analysis, identification, segmentation. Fuzzy image processing.
Using fractals to encode images. The perceptron images.
Dragons are formidable problems in qualitative physics,
challenging, and yet solvable using little or even no algebra or calculus.
e.g. Which direction does the yoyo roll?
What if the table were greased?
Personal Home Page of Dr
Harvey A. Cohen of Melbourne Australia