For many years now the SPIRES database at SLAC has been used to produce a list of the most frequently cited papers during each year. Since 1997 Michael Peskin has been doing this, while at the same time writing up a description of what is in the 40 or so most popular papers, together with comments on what this data shows about trends in particle physics. The 2003 edition of Peskin’s review has recently appeared.
Peskin notes that SPIRES has begun indexing more astrophysical papers during the last two years, and many particle physicists have turned their attention to cosmology. He has expanded the number of top papers he reviews from 40 to 50 to take into account the greater coverage of the database.
The most frequently cited article, this year and every year, is the Particle Data Group’s “Review of Particle Physics” compilation of experimental particle physics data. It is conventional for experimental papers to often refer to this instead of to the original papers. This year the number two and three positions are held by papers from the WMAP experiment, with number four the original results on high redshift supernovae that indicated a non-zero cosmological constant.
The first particle theory paper is the Randall-Sundrum one at number five, and Maldacena’s AdS/CFT paper is at number seven. For many years the top part of this list was heavily dominated by relatively new string theory papers, but the situation is now dramatically different. The highest-ranked post-1999 paper is one about PP-waves at number 18, the next is one at number 37 by Ashoke Sen about time-dependent backgrounds. The only other post-1999 paper in the top 50 is the Dijkgraaf-Vafa paper about supersymmetric gauge theories, which is at number 39.
This list provides pretty conclusive evidence that the field of particle theory more or less flat-lined about 5 years ago, with only a small number of minor blips of brain activity since then.
There’s also a cumulative list of the most highly cited papers of all time. Here the dramatic movement one can watch is the speed with which Maldacena’s paper accumulates citations. At the end of last year it was at number 6 on the list of all-time most frequently cited papers; it has now moved to number 5 and soon will overtake number 4. Within a couple of years it should be at number three, only outranked by the Review of Particle Properties and Weinberg’s original paper on the Weinberg-Salam model.
The SPIRES numbers are probably quite accurate for the last ten years or so (and thus for the Maldacena paper), since just about all particle papers are at the arXiv. Their coverage is less good for older papers.
In any case, people sooner or later stop referring to older papers as they become part of the common lore of the field. I’m suprised that so many people continue to refer to Weinberg’s paper, since the standard model is now so well-entrenched.
Is there a possible “undercounting” of older papers that have become “common knowledge”, such as Weinberg’s 1967 lepton paper? It seems like once something becomes common knowledge or “textbook material”, people seem to cite it less and less. These days how many people still cite the old Schrodinger and Dirac papers from the 1920’s on their respective equations?
How many citations of these older papers would be missed in the spires database? It would be interesting to see how many citations show up for them in the citation indicies, coming from papers which do not show up on spires (ie. long forgotten papers and/or papers published in obscure journals that nobody cares about).
Would it be a safe bet to say that the citations on the Maldacena AdS/CFT paper on spires, has had a reasonable and accurate tracking of it? It would seem that almost every paper that would have cited it, would have been submitted to the arxiv preprint server. Perhaps even crackpot papers (that slipped through the cracks onto arxiv) which cited it, would have also been tracked too.
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