Strong evidence for dual superconformal symmetry in N = 6 superconformal Chern-Simons theory has fueled expectations that the AdS/CFT dual geometry AdS4 × CP 3 is self-dual under T-duality. We revisit the problem to identify commuting bosonic and fermionic isometries in a systematic fashion and show that fermionic T-duality, a symmetry originally proposed by Berkovits & Maldacena, inevitably leads to a singularity in the dilaton transformation. We show that TsT deformations commute with fermionic T-duality and comment on T-duality in the corresponding sigma model. Our results rule out self-duality based on fermionic T-duality for AdS4 × CP 3 or its TsT deformations, but leave the door open for new possibilities.
INTRODUCTIONThe AdS/CFT correspondence is best understood as an equivalence between N = 4 super Yang-Mills (sYM) and type IIB string theory on AdS 5 × S 5 [1]. New ideas incubated in this unique setting quickly percolate to less familiar forms of the duality, where generality may be tested. A duality between superconformal N = 6 ChernSimons (ABJM) theory and type IIA superstrings on AdS 4 × CP 3 [2] represents the first challenge.For AdS 5 /CFT 4 , it is well-known that integrability is present in the planar limit of N = 4 sYM and also strings on AdS 5 × S 5 [3,4], allowing one to connect perturbative regimes of both descriptions. Integrability is believed to play a substantial rôle in relations between scattering amplitudes and Wilson loops [5][6][7][8], as well as the emergence of a hidden superconformal symmetry [9], whose closure with the original superconformal symmetry leads at tree level to Yangian symmetry [10,11], a recognisable integrable structure. Moreover, this so-called "dual superconformal symmetry" can be traced back to a selfmapping of the geometry AdS 5 ×S 5 under a combination of bosonic and fermionic T-dualities [12][13][14].Subsequent developments for ABJM theory largely parallel N = 4 sYM. Integrability is again a feature of the planar limit [15,16] and string theory on AdS 4 ×CP 3 [17][18][19][20]. Moreover, perturbative calculations provide convincing evidence for amplitude/Wilson loop duality [21,22], dual superconformal [23][24][25][26] and Yangian symmetry [27,28]. The similarities between AdS 5 /CFT 4 and AdS 4 /CFT 3 duality are striking and led to the hope that a self-dual mapping of the geometry AdS 4 × CP 3 under a combination of bosonic and fermionic T-dualities could also account for the observed perturbative symmetries in ABJM theory. In this letter we show that the Berkovits-Maldacena transformation [13] inevitably leads to a singularity in the dilaton shift, so self-duality based on fermionic T-duality can not work for AdS 4 × CP 3 .This result may come as no great surprise, since we have witnessed a number of no-go results of varying rigour [29][30][31][32][33][34]. Despite this, none are completely satisfactory. Earlier statements, e. g. [29,30], fail to take account of the chirality and the results of ref. [32], whose approach we follow, fail to be comprehensive in...