Citation
Lass, Harry (1948) Differential geometry of a space with a twopoint differential metric. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/8JJQ1Y83. https://resolver.caltech.edu/CaltechETD:etd08262008151031
Abstract
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In this thesis we have generalized the Riemannian line element […] to the case where […] is a function of two points, x1, x2, and we consider the differential geometry of the line element […].
The extremalizing of L = […] leads to a pair of curves […], called dyodesics, these curves being obvious generalizations of the geodesics of Riemannian geometry. A projective geometry of these paths is then investigated.
We then introduce a concept of parallel displacement of vectors relative to two paths […] which is directly analagous to parallel displacement in a Riemannian space. Parallel displacement is found to depend in a very natural way on six fundamental twopoint tensors, the vanishing of these tensors implying that the space is flat, and for this case the dyodesics take the simple forms […] for special coordinate systems.
From the definition of parallel displacement arises a method for generating new twopoint tensor fields by a process equivalent to covariant differentiation in Riemannian geometry. Parallel vector fields and ennuples of vectors are then introduced. It is shown that the ennuples […], […], form parallel vector fields for the metric space […]. We then define parallel displacement in subspaces and introduce a generalized covariant differentiation process, this last enabling us to develop second fundamental forms for hypersurfaces. It is found that special and important types of coordinate systems may be set up independently at the points M1, and M2. These coordinates enable us to generate new tensors by a method of extension. An equivalence problem is then studied.
Finally, a line element […] is introduced for two masses at M1, M2, the […] satisfying […], the T's corresponding to the Ricci tensor of Riemannian geometry. The dyodesics obtained for this space approximate the Einstein solution for the one body problem when the mass of the particle at M, is small compared with that at M2. The motion for two equal masses differs from that obtained by Robertson in his solution of the equations of motion obtained by Einstein, Infeld, and Hoffman. The difference lies in the yet undetermined periastron effect for double stars.
Item Type:  Thesis (Dissertation (Ph.D.)) 

Degree Grantor:  California Institute of Technology 
Division:  Physics, Mathematics and Astronomy 
Major Option:  Mathematics 
Thesis Availability:  Public (worldwide access) 
Research Advisor(s): 

Thesis Committee: 

Defense Date:  1 January 1948 
Record Number:  CaltechETD:etd08262008151031 
Persistent URL:  https://resolver.caltech.edu/CaltechETD:etd08262008151031 
DOI:  10.7907/8JJQ1Y83 
Default Usage Policy:  No commercial reproduction, distribution, display or performance rights in this work are provided. 
ID Code:  3235 
Collection:  CaltechTHESIS 
Deposited By:  Imported from ETDdb 
Deposited On:  26 Aug 2008 
Last Modified:  20 Dec 2019 19:37 
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