TY - JOUR
T1 - A counterexample to the a-'theorem'
AU - Shapere, Alfred D.
AU - Tachikawa, Yuji
PY - 2008
Y1 - 2008
N2 - We exhibit a renormalization group flow for a four-dimensional gauge theory along which the conformal central charge a increases. The flow connects the maximally superconformal point of an = 2 gauge theory with gauge group SU(N+1) and Nf = 2N flavors in the ultraviolet, to a strongly-coupled superconformal point of the SU(N) gauge theory with Nf = 2N massless flavors in the infrared. Our example does not contradict the proof of the a-theorem via a-maximization, due to the presence of accidental symmetries in the infrared limit. Nor does it contradict the holographic a-theorem, because these gauge theories do not possess weakly-curved holographic duals.
AB - We exhibit a renormalization group flow for a four-dimensional gauge theory along which the conformal central charge a increases. The flow connects the maximally superconformal point of an = 2 gauge theory with gauge group SU(N+1) and Nf = 2N flavors in the ultraviolet, to a strongly-coupled superconformal point of the SU(N) gauge theory with Nf = 2N massless flavors in the infrared. Our example does not contradict the proof of the a-theorem via a-maximization, due to the presence of accidental symmetries in the infrared limit. Nor does it contradict the holographic a-theorem, because these gauge theories do not possess weakly-curved holographic duals.
KW - Extended supersymmetry
KW - Supersymmetric gauge theory
KW - Supersymmetry and duality
UR - http://www.scopus.com/inward/record.url?scp=62649159892&partnerID=8YFLogxK
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U2 - 10.1088/1126-6708/2008/12/020
DO - 10.1088/1126-6708/2008/12/020
M3 - Article
AN - SCOPUS:62649159892
SN - 1126-6708
VL - 2008
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
IS - 12
M1 - 020
ER -