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.