We consider various curious features of general relativity, and relativistic field theory, in two spacetime dimensions. In particular, we discuss: the vanishing of the Einstein tensor; the failure of an initial-value formulation for vacuum spacetimes; the status of singularity theorems; the non-existence of a Newtonian limit; the status of the cosmological constant; and the character of matter fields, including perfect fluids and electromagnetic fields. We conclude with a discussion of what constrains our understanding of physics in different dimensions.
|Original language||English (US)|
|Number of pages||14|
|Journal||Studies in History and Philosophy of Science Part B - Studies in History and Philosophy of Modern Physics|
|State||Published - Aug 2018|
Bibliographical noteFunding Information:
This paper is partially based upon work supported by the John Templeton Foundation grant “Laws, Methods, and Minds in Cosmology” (grant number 59773 ). It was originally conceived when three of us (Fletcher, Manchak, and Weatherall) were students in David Malament's general relativity course, in a previous Aeon. We are grateful to David for many discussions related to this material, and to Brian Pitts and two anonymous referees for helpful comments on a previous version. Weatherall wrote a substantial portion of this paper while a Visiting Fellow at the Australian National University ; he is grateful for their support. Fletcher acknowledges the support of the European Commission through a Marie Curie Fellowship ( PIIF-GA-2013- 628533 ) during the writing of this paper.