Because of the New York Times article discussed here, four recent papers by Nielsen and Ninomiya have been getting a lot of attention in the blogosphere. Pretty much all of it has been unremittingly hostile, when not convinced that these papers must be some sort of joke (except for this from Sean Carroll). I just noticed that these papers have gotten some attention from administrators of the arXiv, who have decided to reclassify three of them, presumably since the appearance of the NYT article.
The first in the series, arXiv:0707.1919 was originally posted in hep-ph, with a cross-listing to hep-th (see the Google cache of Oct. 5), but has now been re-classified as gen-ph (cross-listed as hep-ph and hep-th). Similarly, arXiv:0711.3080 has been reclassified from hep-ph to gen-ph, cross-listed to hep-ph (see Google cache of Sept. 12). I’m not sure what arXiv:0802.2991 was originally classified as, but the Sept. 3 Google cache has it as the same as now, gen-ph, cross-listed to hep-th. Finally, the most recent one, arXiv:0910.0359, was originally classified as hep-ph (Google cache of Oct. 7), now it has been re-classified to gen-ph, cross-listed to hep-ph.
While the arXiv administrators seem to be indicating that they share the common opinion that these are crackpot papers, one thing there does remain constant: trackbacks appear there to various press stories and blog postings about these papers, but trackbacks to this blog seem to be censored.
Update: Trackbacks to blog postings here on this Nielsen-Ninomiya subject have now appeared. The ways of the arXiv remain mysterious to me. About all I can tell is that trackbacks to some sources appear more or less immediately, presumably automatically (for instance the trackbacks to the original NYT article). For other sources, e.g. this one, they only appear in batches, often several days later, presumably after someone has gotten around to considering the matter…