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Brenno Carlini Vallilo

Publications and source records attributed to Brenno Carlini Vallilo.

At least 19 recordsLinked to original sources

A Split-Signature Type IIB Background on $\mathrm{AdS}_{5,\mathbb C}$

We construct a maximally supersymmetric Type IIB background in signature $(5,5)$ on the real ten-manifold underlying complex $\mathrm{AdS}_5$. The spacetime is diffeomorphic to $T^*S^5$ and carries the invariant metric $G=\mathrm i(\bar q-q)$, where $q$ is the holomorphic constant-curvature metric. The real five-form $F_5=(4\mathrm i/L)(Ω-\barΩ)$, built from its normalized volume form, is self-dual, and its stress tensor supports this scalar-flat, non-Einstein metric. We derive these fields from the most general $\mathrm{SL}(4,\mathbb C)$-invariant metric and five-form ansatz: self-duality and the Einstein equation fix their phases up to the overall scale, orientation, and flux sign. The fields obey the reality conditions of the untwisted $\mathrm{IIB}_5$ theory. The holomorphic coframe makes the supercovariant curvature cancellation explicit, and flat transport gives thirty-two global real Killing spinors. Their Killing superalgebra is the factor-exchanging real form of $\mathfrak{psl}(4|4,\mathbb C)$, and we identify the corresponding supercoset.

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Unfolding the Exotic Supergravity Multiplet

We provide an unfolded formulation of linearised 6D exotic supergravity with manifest superconformal symmetry including conformal duality transformations. The construction is based on a superoscillator realisation of the metaplectic supergroup $MOSp(16|16)$ containing the Howe dual pair $MOSp(8^\ast|8)\times SU(2)$. Exotic graviton potentials arise in conformally dual pairs of two-forms in direct products of $SU(2)$-triplets and supertraceless graded-symmetric rank-two supertensors of $OSp(8^\ast|8)$ generated from a hypercharge by the supercharges, providing an analogue of the adjoint representation of $\mathfrak{psu}(2,2|4)$. The potentials are sourced via relative Chevalley-Eilenberg cocycles by a conformally dual pair of chiral and anti-chiral Weyl zero-forms valued in $SO(1,1)\times Spin(1,5)\times USp(8)$-covariant monomorphic restrictions of an extended supersingleton, i.e., an infinite-dimensional $SU(2)$-invariant Hermitian left-module of $MOSp(8^\ast|8)$ containing various irreps associated with different boundary conditions, including the unitarizable exotic supergravity multiplet. Two natural quadratic observables are i) an on-shell closed zero-form built from the chiral Weyl zero-form and its dual, akin to the on-shell value of the second Chern class on the internal twistor $Z$-space of 4D Vasiliev systems; and ii) an off-shell topological six-form built from the conformally dual pair of two-form potentials, reducing on-shell to a generating function for chiral two-point functions in super-Poincaré backgrounds.

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D-branes and nonlinear interactions in the $AdS$ pure spinor string

We develop a coordinate-independent algebraic description of zero-field boundary conditions for the pure spinor string on $AdS_5\times S^5$ in the closed-string channel. The construction is organized by involutive automorphisms of $\mathfrak{psu}(2,2|4)$ that exchange the odd sectors of the $\mathbb Z_4$ grading. Their fixed subalgebras provide candidate half-BPS, Lorentzian D-brane geometries with vanishing background world-volume flux, consistent with the standard $AdS_2$, $AdS_3\times S^1$, $AdS_4\times S^2$, and related embeddings. Together, the seven representatives realize the Lorentzian zero-flux D1, D3, D5, and D7 probe sectors considered here. We then construct a local ansatz for the matter and ghost boundary interactions and derive a system of consistency equations for the tangential superconnection, transverse embedding, and four ghost-gluing couplings. The resulting system is a set of Dirac-Born-Infeld-like equations of motion on the brane world-volume.

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A note on conserved worldsheet supercharges in heterotic pure spinor superstring

We study conserved worldsheet charges associated with spacetime supersymmetry in heterotic pure-spinor superstrings on curved ten-dimensional superspace backgrounds. Requiring BRST invariance and worldsheet conservation gives a covariant set of superspace constraints. In flat superspace these conditions reproduce the standard ten-dimensional supersymmetry generator. In curved superspace, they organize the requirements for global supersymmetry in terms of a normalizable spinor superfield.

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Unfolding the Six-Dimensional Tensor Multiplet

We derive a manifestly superconformally covariant unfolded formulation of the free (2,0) tensor multiplet in six spacetime dimensions. The unfolded system consists of an abelian two-form and an infinite-dimensional chiral zero-form containing the system's curvature, matter fields, and their derivatives on-shell, realized using superoscillators. The construction of the cocycle gluing these forms on a general superconformal background goes one step beyond previous results in super-Poincaré backgrounds.

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Compactifications of Type II Supergravities in Superspace

We propose a way to describe compactifications of Type II supergravities with fluxes directly from superspace. The superspace used is the one that arises naturally from the pure spinor superstring. We show how previous results of flux compactifications can be obtained from our method.

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Relating the $b$ ghost and the vertex operators of the pure spinor superstring

The OPE between the composite $b$ ghost and the unintegrated vertex operator for massless states of the pure spinor superstring is computed and shown to reproduce the structure of the bosonic string result. The vanishing of the double pole singularity is Lorentz gauge and the single pole is shown to be equal to the corresponding integrated vertex operator.

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Vertex operators for the plane wave pure spinor string

In this work we give an explicit construction for the vertex operators of massless states in the pure spinor superstring in a plane wave background. The construction is based on the observation that the full action can be divided in two parts, where the simpler one is based on a smaller coset and closely resembles the gauge fixed Green-Schwarz action.

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Ambitwistor superstring in the Green-Schwarz formulation

In this paper we construct the ambitwistor superstring in the Green-Schwarz formulation. The model is obtained from the related pure spinor version. We show that the spectrum contains only ten dimensional supergravity and that kappa symmetry in a curved background implies some of the standard constraints.

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Worldsheet dilatation operator for the $AdS$ superstring

In this work we propose a systematic way to compute the logarithmic divergences of composite operators in the pure spinor description of the $AdS_5\times S^5$ superstring. The computations of these divergences can be summarized in terms of a dilatation operator acting on the local operators. We check our results with some important composite operators of the formalism.

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Ambitwistor pure spinor string in a type II supergravity background

We construct the ambitwistor pure spinor string in a general type II supergravity background in the semi-classical regime. Almost all supergravity constraints are obtained from nilpotency of the BRST charge and further consistency conditions from additional world-sheet symmetries. We also discuss the case of $AdS_5\times S^5$ background.

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AdS pure spinor superstring in constant backgrounds

In this paper we study the pure spinor formulation of the superstring in $AdS_5\times S^5$ around point particle solutions of the classical equations of motion. As a particular example we quantize the pure spinor string in the BMN background.

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