Ground truth? Concept-based communities versus the external classification of physics manuscripts

EPJ Data Science

Table 1 Distribution of articles among categories

Category	\(\boldsymbol{n^{\mathrm{s}}_{2013}}\)	\(\boldsymbol{n^{\mathrm{m}}_{2013}}\)	\(\boldsymbol{n^{\mathrm {s}}_{2014}}\)	\(\boldsymbol{n^{\mathrm{m}}_{2014}}\)
nucl-th	648	1,628	766	1,210
nucl-ex	315	924	324	736
hep-ph	2,625	3,935	3,116	2,885
hep-ex	602	1,726	706	1,225
hep-lat	356	695	419	417
hep-th	1,787	3,717	2,316	2,960
gr-qc	1,118	2,782	1,527	2,204
astro-ph	10,984	3,023	11,445	2,437
physics	4,452	6,479	5,711	4,880
cond-mat	10,549	4,609	11,397	3,538
nlin	392	327	522	905
quant-ph	2,558	3,240	3,187	2,471
math-ph	0	3,789	412	2,668

The number of manuscript submitted during the year y that have been assigned to a given category only (\(n^{\mathrm{s}}_{\mathrm{y}}\)) or to the category and at least one another (\(n^{\mathrm{m}}_{\mathrm{y}}\)). List of categories: theoretical and experimental nuclear physics (nucl-th and nucl-ex, respectively), four branches of high energy physics (hep-ph: phenomenology, hep-ex: experiment, hep-lat: lattice and hep-th: theory), general relativity and quantum cosmology (gr-qc), astrophysics (astro-ph), physics (physics), condensed matter physics (cond-mat), nonlinear science (nlin), quantum physics (quant-ph) and mathematical physics (math-ph).