Physical progress always proceeds on three fronts: observational/experimental, phenomenological--a coherent codifying of the data-- and finally, theoretical--finding a deeper understanding, through general laws, of those descriptions. The present rapid progress of both micro-, as witness the headline "LHC" results, and cosmo-scales, such as the newest "Planck" maps, puts welcome pressure on theory. Our work is on the "deep" theory side, attempting to find hints of possible generalizations of the "standard model", Einstein Gravity, that account for the deviations from its otherwise spectacular successes. Here we especially mean the apparent need for dark matter, which we hope to reduce to geometrical effects rather than by adding on Ptolemaic particles, without giving up the beauty of geometry. Thus, part of our efforts will be to continue our very recent results that exclude the currently popular "massive Gravity", because the latter loses all the beauty of geometry, instead unleashing too many variants and losing the tightness of geometrical description. Indeed, just as the Yang-Mills field theory counterparts of General Relativity were shown to exclude massive extensions, but relied instead on the now LHC-observed Higgs field, it looks as if the beautiful "isolated" nature of our basic interacting "glue" theories, Yang -Mills and Maxwell, will extend to gravity as well. On the constructive side, we intend to look for--less fundamental "effective", non-local but still geometrical, laws that replace the fuzziness of dark matter by additional terms that exploit the freedom remaining in the "Einstein" picture.
In more accessible terms, let us place our efforts within the present framework of front-line Physics, one that has received much recent media attention both in the Laboratory--especially the discovery of the "Higgs" field at the LHC accelerator, and at the opposite end of our universe-- by for example the newest spectacular pictures presented by the Planck, and other Cosmic observatories, of our entire Universe as it looked a mere third of a million years into its expansion the its present 13 billion. Our aim is to understand such general features of our world by--as conservative as possible--extensions of Einstein's General Relativity to account for Dark Matter and other unexpected new large-scale features. The conservative part of our program is to exclude candidates that go too far, by violating the (by now familiar) picture of curved space that General Relativity presents. So our twofold approach keeps a tight rein on that good, "geometrical", part of our hard-won picture of the Universe, while extending its reach within this realm, in particular by exploring different ways in which matter and geometry can interact there. We may be sure that the observational surprises will stay ahead of our inventive abilities, but that's the bootstrap that always works, and illuminates our world!
