We propose a manifestly supersymmetric generalization of the solvable T T deformation of two-dimensional field theories. For theories with (1, 1) and (0, 1) supersymmetry, the deformation is defined by adding a term to the superspace Lagrangian built from a superfield containing the supercurrent. We prove that the energy levels of the resulting deformed theory are determined exactly in terms of those of the undeformed theory. This supersymmetric deformation extends to higher dimensions, where we conjecture that it might provide a higher-dimensional analogue of T T , producing supersymmetric Dirac or Dirac-Born-Infeld actions in special cases.

The TT deformation of a supersymmetric two-dimensional theory preserves the original supersymmetry. Moreover, in several interesting cases the deformed theory possesses additional non-linearly realized supersymmetries. We show this for certain N = (2, 2) models in two dimensions, where we observe an intriguing similarity with known N = 1 models in four dimensions. This suggests that higher-dimensional models with non-linearly realized supersymmetries might also be obtained from TT -like flow equations.We show that in four dimensions this is indeed the case for N = 1 Born-Infeld theory, as well as for the Goldstino action for spontaneously broken N = 1 supersymmetry. arXiv:1910.01599v1 [hep-th] 3 Oct 2019Contents 1 Introduction 1 2 D = 2 N = (2, 2) Flows and Non-Linear N = (2, 2) Supersymmetry 4 2.1 TT deformations with N = (2, 2) supersymmetry 4 2.2 The TT -deformed twisted-chiral model and partial-breaking 7 2.3 The TT -deformed chiral model and partial-breaking 13 3 D = 4 T 2 Deformations and Their Supersymmetric Extensions 16 3.1 Comments on the T 2 operator in D = 4 16 3.2 D = 4 N = 1 supercurrent-squared operator 18 4 Bosonic Born-Infeld As a T 2 Flow 20 5 Supersymmetric Born-Infeld From Supercurrent-Squared Deformation 22 7 Conclusions and Outlook 33 A Deriving a Useful On-shell Identity 36 construct two models describing the partial supersymmetry breaking pattern N = (4, 4) → N = (2, 2) in D = 2. These models have manifest N = (2, 2) supersymmetry from the superspace structure used in their construction, but they also admit another hidden nonlinear N = (2, 2) supersymmetry. It turns out the resulting actions are exactly the same as the N = (2, 2) chiral and twisted chiral TT -deformed actions of [18]. The intriguing relation between non-linear supersymmetry and TT therefore persists for models with manifest N = (2, 2) supersymmetry. Interestingly, even the D = 2 Volkov-Akulov action, describing the dynamics of the Goldstinos which arise from the spontaneous breaking of N = (2, 2) supersymmetry, satisfies a TT flow equation [21]. This collection of examples motivates us to see whether any higher-dimensional theories with non-linear supersymmetries might also satisfy TT -like flow equations. It has been known for more than two decades that the Bagger-Galperin action for the D = 4 N = 1 Born-Infeld theory describes N = 2 → N = 1 partial supersymmetry breaking [22]. Does the Bagger-Galperin action arise from a TT -like deformation of N = 1 Maxwell theory? That the linear order deformation is given by a supercurrent-squared operator was noted long ago in [23]. Much more recently, bosonic Born-Infeld theory was shown to satisfy a T 2 flow equation, where T 2 is an operator quadratic in the stress-energy tensor [24]. In this work, we explicitly show that the Bagger-Galperin action indeed satisfies a supercurrentsquared flow equation, generalizing the observation of [23] to all orders in the deformation parameter. The supercurrent-squared deformation operator is constructed from supercurrent multiplets, but its to...

We construct a solvable deformation of two-dimensional theories with (2, 2) supersymmetry using an irrelevant operator which is a bilinear in the supercurrents.This supercurrent-squared operator is manifestly supersymmetric, and equivalent to T T after using conservation laws. As illustrative examples, we deform theories involving a single (2, 2) chiral superfield. We show that the deformed free theory is on-shell equivalent to the (2, 2) Nambu-Goto action. At the classical level, models with a superpotential exhibit more surprising behavior: the deformed theory exhibits poles in the physical potential which modify the vacuum structure. This suggests that irrelevant deformations of T T type might also affect infrared physics. arXiv:1906.00467v2 [hep-th]

The Dirac action describes the physics of the Nambu-Goldstone scalars found on branes. The Born-Infeld action defines a non-linear theory of electrodynamics. The combined Dirac-Born-Infeld (DBI) action describes the leading interactions supported on a single D-brane in string theory. We define a non-abelian analogue of DBI using the T T deformation in two dimensions. The resulting quantum theory is compatible with maximal supersymmetry and such theories are quite rare.

We show that the T T deformation of two-dimensional quantum field theory on AdS 2 is well-defined and solvable at the quantum level. Flow equations for the energy spectrum and partition function are derived in analogy with the flat space case. As a non-trivial check, we perturbatively compute the deformed energy spectrum for the case of a free scalar field. We analyze the high energy density of states of the deformed theory and find a Hagedorn growth of states.