IIA Theory Research Articles

Nonrelativistic strings and the limits of mathcal{N} = 2 dualities

We carry out the formulation of nonrelativistic (NR) F-string theory for mathcal{N} = 2 Gaiotto-Maldacena class of geometries in type IIA supergravity. Considering the NS-NS sector, we reduce the type IIA theory into the NR sigma models those are formulated over the nonrelativistic target space geometries known as the torsional String Newton-Cartan (TSNC) backgrounds. Using these TSNC data, we write down the sigma model action and explore several properties in the semiclassical limit. In particular, we carry out the canonical analysis of the T-duality transformation rules in TSNC background. Following the standard canonical prescription of obtaining T-duality transformations, we map these TSNC sigma models to relativistic sigma models propagating over general relativity backgrounds. Finally, we conclude with a detailed discussion on the effects of adding flavour branes and thereby taking the corresponding TSNC limit in the bulk description of mathcal{N} = 2 quivers. We compute various field theory observables in the nonrelativistic limit and outline the structure of the NR Lagrangian following the light cone reduction of mathcal{N} = 2 SYM theory.

Exceptional Algebroids and Type IIA Superstrings

AbstractWe study exceptional algebroids in the context of warped compactifications of type IIA string theory down to n dimensions, with . In contrast to the M‐theory and type IIB case, the relevant algebroids are no longer exact, and their locali moduli space is no longer trivial, but has 5 distinct points. This relates to two possible scalar deformations of the IIA theory. The proof of the local classification shows that, in addition to these scalar deformations, one can twist the bracket using a pair of 1‐forms, a 2‐form, a 3‐form, and a 4‐form. Furthermore, we use the analysis to translate the classification of Leibniz parallelisable spaces (corresponding to maximally supersymmetric consistent truncations) into a tractable algebraic problem. We finish with a discussion of the Poisson–Lie U‐duality and examples given by tori and spheres in 2, 3, and 4 dimensions.

Subleading corrections to the S3 free energy of necklace quiver theories dual to massive IIA

We investigate the S3 free energy of mathcal{N} = 3 Chern-Simons-matter quiver gauge theories with gauge group U(N)r (r ≥ 2) where the sum of Chern-Simons levels does not vanish, beyond the leading order in the large-N limit. We take two different approaches to explore the sub-leading structures of the free energy. First we evaluate the matrix integral for the partition function in the ’t Hooft limit using a saddle point approximation. Second we use an ideal Fermi-gas model to compute the same partition function, but in the limit of fixed Chern-Simons levels. The resulting expressions for the free energy F = − log Z are then compared in the overlapping parameter regime. The Fermi-gas approach also hints at a universal frac{1}{6} log N correction to the free energy. Since the quiver gauge theories we consider are dual to massive Type IIA theory, we expect the sub-leading correction of the planar free energy in the large ’t Hooft parameter limit to match higher-derivative corrections to the tree-level holographic dual free energy, which have not yet been fully investigated.

Janus solutions from dyonic ISO(7) maximal gauged supergravity

We give a large class of new supersymmetric Janus solutions in dyonic ISO(7) maximal gauged supergravity encompassing all known solutions appearing recently. We consider SO(3) invariant sector in which the gauged supergravity admits four supersymmetric AdS4 vacua with N = 1, 1, 2, 3 unbroken supersymmetries and G2, SU(3), SU(3) × U(1) and SO(4) symmetries, respectively. We find Janus solutions preserving N = 1, 2, 3 supersymmetries and interpolating between AdS4 vacua and the N = 8 SYM phase. These solutions can be interpreted as conformal interfaces between SYM and various conformal phases of the dual field theory in three dimensions. The solutions can also be embedded in massive type IIA theory by a consistent truncation on S6. We also find a number of singular Janus solutions interpolating between N = 8 SYM or AdS4 vacua and singularities or between singular geometries. It turns out that, apart from the SYM phase on D2-branes, all the singularities arising in these solutions are unphysical in both four- and ten-dimensional frameworks.

Dynamical Cobordism and Swampland Distance Conjectures

We consider spacetime-dependent solutions to string theory models with tadpoles for dynamical fields, arising from non-trivial scalar potentials. The solutions have necessarily finite extent in spacetime, and are capped off by boundaries at a finite distance, in a dynamical realization of the Cobordism Conjecture. We show that as the configuration approaches these cobordism walls of nothing, the scalar fields run off to infinite distance in moduli space, allowing to explore the implications of the Swampland Distance Conjecture. We uncover new interesting scaling relations linking the moduli space distance and the SDC tower scale to spacetime geometric quantities, such as the distance to the wall and the scalar curvature. We show that walls at which scalars remain at finite distance in moduli space correspond to domain walls separating different (but cobordant) theories/vacua; this still applies even if the scalars reach finite distance singularities in moduli space, such as conifold points.We illustrate our ideas with explicit examples in massive IIA theory, M-theory on CY threefolds, and 10d non-supersymmetric strings. In 4d mathcal{N} = 1 theories, our framework reproduces a recent proposal to explore the SDC using 4d string-like solutions.

Holographic entanglement entropy for Lif4(2)×S1×S5 spacetime with string excitations

The (F1,D2,D8) brane configuration with $Lif_4^{(2)}\times {S}^1\times S^5$ geometry is a known Lifshitz vacua supported by massive $B_{\mu\nu}$ field in type IIA theory. This system allows exact IR excitations which couple to massless modes of the fundamental string. Due to these massless modes the solutions have a flow to a dilatonic $Lif_4^{(3)}\times S^1\times S^5$ vacua in IR. We study the entanglement entropy on the boundary of this spacetime for the strip and the disc subsystems. To our surprise net entropy density of the excitations at first order is found to be independent of the typical size of subsystems. We interpret our results in the light of first law of entanglement thermodynamics.

Non-integrability in AdS3 vacua

We ask the question of classical integrability for certain (classes of) supergravity vacua that contain an AdS3 factor arising in massive IIA and IIB theories and realizing various and different amounts of supersymmetry. Our approach is based on a well-established method of analytic non-integrability for Hamiltonian systems. To detect a non-integrable sector we consider a non-trivially wrapped string soliton and study its fluctuations. We answer in the negative for each and every one of the supergravity solutions. That is, of course, modulo very specific limits where the metrics reduce to the AdS3 × S3 × {tilde{S}}^3 × S1 and AdS3 × S3 × T4 solutions which are known to be integrable.

Lost chapters in CHL black holes: untwisted quarter-BPS dyons in the \u21242 model

Motivated by recent advances in Donaldson-Thomas theory, four-dimensional mathcal{N} = 4 string-string duality is examined in a reduced rank theory on a less studied BPS sector. In particular we identify candidate partition functions of “untwisted” quarter-BPS dyons in the heterotic ℤ2 CHL model by studying the associated chiral genus two partition function, based on the M-theory lift of string webs argument by Dabholkar and Gaiotto. This yields meromorphic Siegel modular forms for the Iwahori subgroup B(2) ⊂ Sp4(ℤ) which generate BPS indices for dyons with untwisted sector electric charge, in contrast to twisted sector dyons counted by a multiplicative lift of twisted-twining elliptic genera known from Mathieu moonshine. The new partition functions are shown to satisfy the expected constraints coming from wall-crossing and S-duality symmetry as well as the black hole entropy based on the Gauss-Bonnet term in the effective action. In these aspects our analysis confirms and extends work of Banerjee, Sen and Srivastava, which only addressed a subset of the untwisted sector dyons considered here. Our results are also compared with recently conjectured formulae of Bryan and Oberdieck for the partition functions of primitive DT invariants of the CHL orbifold X = (K3 × T2)/ℤ2, as suggested by string duality with type IIA theory on X.

Subleading corrections to the free energy in a theory with N5/3 scaling

We numerically investigate the sphere partition function of a Chern-Simons-matter theory with SU(N) gauge group at level k coupled to three adjoint chiral multiplets that is dual to massive IIA theory. Beyond the leading order N5/3 behavior of the free energy, we find numerical evidence for a term of the form (2/9) log N. We conjecture that this term may be universal in theories with N5/3 scaling in the large-N limit with the Chern-Simons level k held fixed.

AdS2 type-IIA solutions and scale separation

In this note we examine certain classes of solutions of IIA theory without sources, of the form AdS2× ℳ(1) × ⋯ × ℳ(n), where ℳ(i) are Riemannian spaces. We show that large hierarchies of curvatures can be obtained between the different factors, however the absolute value of the scalar curvature of AdS2 must be of the same order or larger than the absolute values of the scalar curvatures of all the other factors.

Modular forms as classification invariants of 4D mathcal{N} = 2 Heterotic-IIA dual vacua

We focus on 4D mathcal{N} = 2 string vacua described both by perturbative Heterotic theory and by Type IIA theory; a Calabi-Yau three-fold XIIA in the Type IIA language is further assumed to have a regular K3-fibration. It is well-known that one can assign a modular form Φ to such a vacuum by counting perturbative BPS states in Heterotic theory or collecting Noether-Lefschetz numbers associated with the K3-fibration of XIIA. In this article, we expand the observations and ideas (using gauge threshold correction) in the literature and formulate a modular form Ψ with full generality for the class of vacua above, which can be used along with Φ for the purpose of classification of those vacua. Topological invariants of XIIA can be extracted from Φ and Ψ, and even a pair of diffeomorphic Calabi-Yau’s with different Kähler cones may be distinguished by introducing the notion of “the set of Ψ’s for Higgs cascades/for curve classes”. We illustrated these ideas by simple examples.

String coherent vertex operators of Neveu-Schwarz and Ramond states

We present a compact expression for a coherent vertex operator in superstring theory, in the Neveu-Schwarz sector, that can be easily extended to the Ramond sector by supersymmetric transformations in target space. We give also an explicit construction for the Ramond coherent vertex operator. These constructions provide the use of the supersymmetric version of the Del Giudice-Di Vecchia-Fubini operators and Operator Product Expansion techniques, displaying manifest BRST invariance and after normal ordering also manifest covariance. As a consistency check we compute tree level three-point scattering amplitudes involving Neveu-Schwarz coherent vertex operators in different superghost pictures. Extending these results to the closed superstring, we give the expressions of the coherent vertex operators in the case of type IIA and IIB theories.

Supersymmetric solutions of 7D maximal gauged supergravity

We study a number of supersymmetric solutions in the form of $Mkw_3\times S^3$- and $AdS_3\times S^3$-sliced domain walls in the maximal gauged supergravity in seven dimensions. These solutions require non-vanishing three-form fluxes to support the $AdS_3$ and $S^3$ subspaces. We consider solutions with $SO(4)$, $SO(3)$, $SO(2)\times SO(2)$ and $SO(2)$ symmetries in $CSO(p,q,5-p-q)$, $CSO(p,q,4-p-q)$ and $SO(2,1)\ltimes \mathbf{R}^4$ gauge groups. All of these solutions can be analytically obtained. For $SO(5)$ and $CSO(4,0,1)$ gauge groups, the complete truncation ansatze in terms of eleven-dimensional supergravity on $S^4$ and type IIA theory on $S^3$ are known. We give the full uplifted solutions to eleven and ten dimensions in this case. The solutions with an $AdS_3\times S^3$ slice are interpreted as two-dimensional surface defects in six-dimensional $N=(2,0)$ superconformal field theory in the case of $SO(5)$ gauge group or $N=(2,0)$ nonconformal field theories for other gauge groups. For $SO(4)$ symmetric solutions, it is possible to find solutions with both the three-form fluxes and $SO(3)$ gauge fields turned on. However, in this case, the solutions can be found only numerically. For $SO(3)$ symmetric solutions, the three-form fluxes and $SO(3)$ gauge fields cannot be non-vanishing simultaneously.

On scale separation in type II AdS flux vacua

We study the separation of AdS and Kaluza-Klein (KK) scales in type II 4d AdS orientifold vacua. We first address this problem in toroidal/orbifold type IIA vacua with metric fluxes, corresponding to compactifications in twisted tori, both from the 4d and 10d points of view. We show how the naive application of the effective 4d theory leads to results which violate the AdS distance conjecture, in a class of mathcal{N} = 1 supersymmetric models which have a 10d lifting to a compactification on S3× S3. We show how using KK scales properly modified by the compact metric leads to no separationof scales with {M}_{mathrm{KK}}^2=mathfrak{c}left|Lambda right|, with c a numerical constant independent of fluxes. This applies with no need to keep non-leading fluxes fixed. We also consider a class of IIB models with non-geometric fluxes in which the effective field theory analysis seems to lead to a naive separation of scales and a violation of the AdS distance conjecture. It has a T-dual which again may be understood as a 10d type IIA theory compactified on S3× S3. In this geometric dual one again observes that the strong AdS distance conjecture is obeyed with {M}_{mathrm{KK}}^2=mathfrak{c}^{prime}left|Lambda right|, if one takes into account the curvature in the internal space. These findings seem to suggest that all toroidal/orbifold models with fluxes in this class obey {M}_{mathrm{KK}}^2=mathfrak{c}left|Lambda right| with mathfrak{c} a flux-independent numerical constant.

Enhancement of axion decay constants in type IIA theory?

We investigate the possibility of enhancement of effective axion decay constant in well controlled constructions in string theory. To this end, we study the dynamics of axions arising in the compactifications of type IIA string theory on Calabi-Yau orientifolds with background fluxes (with non-perturbative effects included to ensure stabilization of all moduli). In this setup, we attempt to obtain large effective axion decay constant in two different ways: by searching for a direction in field space in which the potential is sufficiently flat and by arriving at a very explicit stringy embedding of the Kim-Nilles-Peloso (KNP) alignment mechanism. We do not find super-Planckian effective decay constants by either of the approaches. Furthermore, we find that the alignment angle of KNP mechanism can not be made arbitrarily small by adjusting the fluxes.

On matrix description of D-branes

We study the low energy dynamics of a single Dp-brane carrying sufficient large number of D0-brane charges in type IIA theory. We assume the D-brane topology to be R×M2n, where M2n is a closed manifold admitting a symplectic structure. We propose a new gauge fixing condition which eliminates the spatial gauge fluctuations on the Dp-brane. Using a conventional regularization method, one finds that the dynamics is characterized by D0-brane matrix description when the density of D0-branes is large enough. We also calculate the leading order interactions between two D2-branes carrying both electric and magnetic fluxes in matrix theory.

Supersymmetric domain walls in 7D maximal gauged supergravity

We give a large class of supersymmetric domain walls in maximal seven-dimensional gauged supergravity with various types of gauge groups. Gaugings are described by components of the embedding tensor transforming in representations mathbf {15} and overline{mathbf {40}} of the global symmetry SL(5). The embedding tensor in mathbf {15} representation leads to CSO(p,q,5-p-q) gauge groups while gaugings in overline{mathbf {40}} representation describes CSO(p,q,4-p-q) gauge groups. These gaugings admit half-supersymmetric domain walls as vacuum solutions. On the other hand, gaugings involving both mathbf {15} and overline{mathbf {40}} components lead to frac{1}{4}-supersymmetric domain walls. In this case, the gauge groups under consideration are SO(2,1)ltimes mathbf {R}^4 and CSO(2,0,2)sim SO(2)ltimes mathbf {R}^4. All of the domain wall solutions are analytically obtained. For SO(5) gauge group, the gauged supergravity admits an N=4 supersymmetric AdS_7 vacuum dual to N=(2,0) SCFT in six dimensions. The corresponding domain walls can be interpreted as holographic RG flows from the N=(2,0) SCFT to non-conformal N=(2,0) field theories in the IR. The solutions can be uplifted to eleven dimensions by using a truncation ansatz on S^4. Furthermore, the gauged supergravity with CSO(4,0,1)sim SO(4)ltimes mathbf {R}^4 gauge group can be embedded in type IIA theory via a truncation on S^3. The uplifted domain walls, describing NS5-branes of type IIA theory, are also given.

RG flows and cascades of Lif4(2)\u2009\xd7\u2009S1\u2009\xd7\u2009S5 vacua

The (F1,D2,D8) brane configuration produces Lif4(2) × S1 × S5 Lifshitz vacua supported by ‘massive’ B-field. We present exact deformations of this system under which new massless B-modes of strings also get excited. Due to these massless modes the deformed solutions flow to conformally Lif4(3) × S1 × S5 vacua in the IR. The latter types are supersymmetric solutions of ordinary type IIA theory. The massive and massless Bμν modes segregate out in the IR. We confirm that the massive B mode and cosmological constant indeed decouple from the theory rendering the IR field dynamics controlled by massless fields only. A similar effect is observed on the UV side of the flow where a relativistic regime reappears. We also present ‘cascading’ Lifshitz vacua in which dynamical exponent has integral jumps along the flow; Lif4(3) → Lif4(2) → Lif4(1). The critical Lif4(2) theory separates ‘deconfining’ Lif4(3) IR theory from the confining Yang-Mills phase in UV.

Yukawa couplings from magnetized D-brane models on non-factorisable tori

We compute Yukawa couplings in type IIB string theory compactified on a non factorisable six-torus in the presence of D9 branes and fluxes. The setting studied in detail, is obtained by T-dualising an intersecting brane configuration of type IIA theory compactified on a torus generated by the SO(12) root lattice. Particular deformations of such torus are taken into account and provide moduli dependent couplings. Agreement with the type IIA result is found in a non trivial way. The classical type IIB calculation gives also information on a factor accessible only by quantum computations on the type IIA side.

Dimensional reductions of DFT and mirror symmetry for Calabi–Yau three-folds and K3 × T2

We perform dimensional reductions of type IIA and type IIB double field theory in the flux formulation on Calabi–Yau three-folds and on K3×T2. In addition to geometric and non-geometric three-index fluxes and Ramond–Ramond fluxes, we include generalized dilaton fluxes. We relate our results to the scalar potentials of corresponding four-dimensional gauged supergravity theories, and we verify the expected behavior under mirror symmetry. For Calabi–Yau three-folds we extend this analysis to the full bosonic action including kinetic terms.