arXiv subjects

Alice Lüscher

Publications and source records attributed to Alice Lüscher.

11 recordsLinked to original sources

arXiv2026

IIB an equivariantly localized puncture

We use equivariant localization to compute various observables for $\mathcal{N}=(2,2)$ preserving AdS$_3$ solutions in type IIB supergravity. Our method for localizing the odd-dimensional internal space is to perform a dimensional reduction along a shrinking circle which introduces a boundary in the remaining even-dimensional spacetime. Canonical even-dimensional localization can then be performed on this space after taking into account contributions from the boundary. We illustrate with a number of supersymmetric solutions. One of the novel aspects of this work is applying these techniques to study punctures and defects using localization. We obtain new results for the central charge of 2d SCFTs arising from compactifying $\mathcal{N}=4$ SYM on a punctured Riemann surface.

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arXiv2026

Ten-dimensional localization

We construct equivariantly closed polyforms for the fluxes and the action of (massive) type IIA and type IIB supergravity directly in ten dimensions. We illustrate applications of our formalism to two distinct classes of solutions in massive type IIA. Our analysis straightforwardly reproduces and vastly generalizes all known results for on-shell actions in these classes, with no need for a consistent truncation. Where known, we match the corresponding field theory partition functions at leading order, and our results extend easily to other solutions of type II supergravity.

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arXiv2026

Probing black holes with equivariant localization

We introduce equivariant localization as a method for computing the action of probe branes in supergravity backgrounds. We apply it to supersymmetric probe D3-branes in type IIB supersymmetric spacetimes obtained by uplifting the Kerr-Newman-AdS$_5$ black hole on a toric Sasaki-Einstein space. Depending on the cycles they wrap, such branes represent non-perturbative corrections to or defect operator insertions in the superconformal index of a large family of four-dimensional $\mathcal{N}=1$ quiver superconformal field theories. The resulting action reduces to equivariant integrals and can be evaluated entirely from toric data.

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arXiv2025

Localizing punctures in M-theory

We use equivariant localization and holography to study four-dimensional $\mathcal{N}=1$ superconformal field theories arising from M5-branes wrapped on a punctured Riemann surface. We explain how, given a Riemann surface with marked points, one can glue in a ``puncture geometry'' locally around each point. Using equivariant localization we show that the central charge consists of a bulk contribution plus localized puncture contributions. We recover and generalize the known results for locally $\mathcal{N}=2$ preserving punctures, and derive new results for genuinely locally $\mathcal{N}=1$ preserving punctures.

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arXiv2025

Equivariant localization for $D=4$ gauged supergravity

We consider supersymmetric solutions of $D=4$, $\mathcal{N}=2$ Euclidean gauged supergravity coupled to an arbitrary number of vector multiplets. Such solutions admit an R-symmetry Killing vector, $ξ$, constructed as a bilinear in the Killing spinor. The Killing spinor bilinears can also be used to construct polyforms that are equivariantly closed under the action of the equivariant exterior derivative $\mathrm{d}_ξ=\mathrm{d}-ξ\mathbin{\rule[.2ex]{.4em}{.03em}\rule[.2ex]{.03em}{.9ex}}\,$. This allows one to compute various flux integrals and the on-shell action using localization, without solving any supergravity equations, just assuming the supersymmetric solutions exist. The flux integrals allow one to obtain important UV-IR relations, relating fixed point data in the bulk to data on the asymptotic AdS boundary, allowing one to express the gravitational free energy in terms of boundary SCFT data. We illustrate the formalism with a number of examples, including classes of solutions which are unlikely to ever be constructed in closed form.

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arXiv2025

Toric gravitational instantons in gauged supergravity

We introduce a general class of toric gravitational instantons in $D=4$, $\mathcal{N}=2$ gauged supergravity, namely Euclidean supersymmetric solutions with $U(1)^2$ isometry. Such solutions are specified by a "supergravity labelled polytope", where the labels encode the 4-manifold topology, the choice of magnetic fluxes, and certain signs associated to the Killing spinor. Equivariant localization then allows us to write down the gravitational free energy for such a solution, assuming it exists, and study its properties. These results open the way for a systematic study of holography in this setting, where the dual large $N$ field theories are defined on the boundary 3-manifolds, which are (squashed) lens spaces $L(p,q)$ or generalizations with orbifold singularities.

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arXiv2025

Localization of the free energy in supergravity

We derive a general formula for the gravitational free energy of Euclidean supersymmetric solutions to $D=4$, $\mathcal{N}=2$ gauged supergravity coupled to vector multiplet matter. This allows one to compute the free energy without solving any supergravity equations, just assuming the solutions exist. As well as recovering some known results in the literature with ease, we also present new supergravity results that match with holographically dual field theory computations.

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arXiv2024

A geometric dual of F-maximization in massive type IIA

Using equivariant localization we construct a geometric dual of F-maximization in massive type IIA supergravity. Our results use only topological data to quantize the fluxes, compute the free-energy and conformal dimensions of operators in the dual field theory without the need for explicit solutions. We utilize our formalism to study various classes of solutions, including examples where an explicit solution is not known.

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arXiv2024

Localization and Attraction

We use equivariant localization to construct off-shell entropy functions for supersymmetric black holes in $\mathcal{N}=2$, $D=4$ gauged supergravity coupled to matter. This allows one to compute the black hole entropy without solving the supergravity equations of motion and provides a novel generalization of the attractor mechanism. We consider magnetically charged black holes in $AdS_4$ which have an $AdS_2\times M_2$ near horizon geometry, where $M_2$ is a sphere or a spindle, and we also obtain entropy functions for ungauged supergravity as a simple corollary. We derive analogous results for black strings and rings in $D=5$ supergravity which have an $AdS_3\times M_2$ near horizon geometry, and in this setting we derive an off-shell expression for the central charge of the dual $\mathcal{N}=(0,2)$, $d=2$~SCFT.

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arXiv2024

Matrix models from black hole geometries

Supersymmetric, magnetically charged (and possibly accelerating) black holes in AdS$_4$ that uplift on Sasaki-Einstein manifolds $Y_7$ to M-theory have a dual matrix model description. The matrix model in turn arises by localization of the 3d $\mathcal{N}=2$ SCFTs, dual to the AdS$_4$ vacuum, on the black hole horizon geometry, which is a Riemann surface $Σ_g$ (or a spindle $Σ$). We identify the imaginary part $t$ of the continuously distributed eigenvalues in the matrix model, and their density function $ρ(t)$, with natural geometric quantities associated with the M-theory circle action $U(1)_M$ on the near-horizon geometry AdS$_2\times Y_9$, the internal space $Y_9$ being a $Y_7$ fibration over $Σ_g$ (or $Σ$). Moreover, we argue that the points where $ρ'(t)$ is discontinuous match with the classical action of BPS probe M2-branes wrapping AdS$_2$ and the M-theory circle. We illustrate our findings with the ABJM and ADHM theories, whose duals have $Y_7 = S^7/\mathbb{Z}_k$, and some of their flavoured variants corresponding to other toric $Y_7$.

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arXiv2022

Positivity bounds in vector theories

Assuming unitarity, locality, causality, and Lorentz invariance of the, otherwise unknown, UV completion, we derive a new set of constraints on the effective field theory coefficients for the most general, ghost-free Generalized Proca and Proca Nuevo massive vector models. For the Generalized Proca model, we include new interactions that had not been previously considered in the context of positivity bounds and find these additional terms lead to a widened parameter space for the previously considered interactions. Although, the Generalized Proca and Proca Nuevo models are inequivalent, we find interesting analogues between the coefficients parameterizing the two models and the roles they play in the positivity bounds.

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