Ancestors of Eric L Peterson from Sweden.

I'm looking for my maternal grandfather's ancestors.  His name was Eric L ("Lee" or "Leonard"; I'm not sure which) Peterson.  He was born in Sweden, probably around 1910.  He was married to Marian Alice Torkelson in Bend, Oregon, and both of them were physics students at the University of Oregon.  Eric Peterson eventually became a physicist and worked at the Los Alamos National Laboratory in New Mexico from about 1945 to 1971 or so.  The couple had 2 children; my mother, Karin Christine Peterson, and my uncle, Eric Lee "Pete" Peterson, Jr..  There are some indications in the records found on ancestry.com that Eric Peterson was the son of Isaac Peterson and Christina Larson, but there is one thing that throws some doubt on that; I have a newspaper clipping announcing Eric and Marian's elopement, and Eric's parents are listed as "Mr. and Mrs. O Peterson".  Now, this could be a typo, but it makes me wonder.  "Isaac" is a long way off from "Olaf" or "Ole" or "Otto".

I also have found practically nothing on Isaac Peterson, other than his birth and death dates (1883 - 1951; born in Sweden, died in Canada) and the fact that he was married to Christina Larson (1880 - 1936).  He did, in fact, have a son names "Eric".

If anyone has any further information, either on Eric Peterson or Isaac Peterson, I would sure appreciate it.

Thanks!
Marian Bumala nee Yearian