arXiv subjects

Fridrik Freyr Gautason

Publications and source records attributed to Fridrik Freyr Gautason.

At least 19 recordsLinked to original sources

arXiv2026

Holographic Tests of the $μ$ Ensemble

We study in detail a recent proposal stating that M-theory observables arising from the quantisation of M2-branes are naturally computed in a fixed $A_3$ ensemble. In a holographic setting this implies that in a semiclassical approximation 11d bulk observables in an asymptotically AdS$_4$ background are computed in a grand canonical ensemble of fixed chemical potential $μ$ conjugate to the integer $N$ determining the rank of the gauge group in the dual CFT. We provide detailed precision tests of holography in the fixed $μ$ ensemble by focusing on the two leading terms in the derivative expansion of the 11d theory. In addition, we study one-loop logarithmic corrections which we compute in detail. For asymptotically AdS$_4\times S^7/\mathbf{Z}_k$ 11d backgrounds our results are in agreement with supersymmetric localisation calculations in the dual ABJM SCFT. Moreover, we employ the logarithmic corrections in the $μ$ ensemble to determine the measure of the integral Laplace transform and use this to compute dual SCFT supersymmetric partition functions, like the superconformal index and the squashed $S^3$ partition function, to all orders in the perturbative $1/N$ expansion in terms of Airy functions in harmony with results and conjectures in the dual SCFT.

hep-th↗

arXiv2026

Universal holographic Wilson loops in 3d SCFTs

We study the vacuum expectation value of half-BPS Wilson loop operators in two families of superconformal $\mathcal{N}=2$ Chern-Simons-matter theories. The first family is dual to AdS$_{4}$ solutions in M-theory, while the second one has a dual description in massive type IIA string theory. Utilizing the properties of the underlying geometry, we provide a universal description for the semiclassical quantization of a probe M2-brane and fundamental string in the respective holographic dual geometries. As a result, we find the one-loop partition function of both the M2-brane and the string which leads to a prediction for the large $N$ behaviour of the Wilson loops in the dual SCFTs. For theories with M-theory duals, we conjecture the full perturbative completion as a ratio of Airy functions.

hep-th↗

arXiv2025

Localisation of the M2-brane

We study quantum M2-branes in holographic backgrounds and show that their moduli spaces of zero-modes are localised according to an R-symmetry Killing vector. We discuss the relation with recent results in the context of equivariant localisation in gauged supergravity and argue its origin within M-theory path integrals expanded in saddle points over M2-branes. We argue that the M2-brane partition function, including its non-perturbative corrections, should be compared to the field theory grand canonical partition function. Our results extend recent observations in the context of the giant graviton expansion of superconformal indices to generic supersymmetric AdS boundary conditions. As a byproduct we predict non-perturbative corrections to a variety of supersymmetric observables of the ABJM theory.

hep-th↗

arXiv2025

Ensembles in M-theory and Holography

We discuss that the string/M-theory partition function requires a choice of ensembles, depending on which background fields are held fixed. The background fields correspond to worldvolume couplings in the effective action approach to the superstring, which we extrapolate to the M2-brane. One natural ensemble in this context, which we call the M2-ensemble, corresponds to fixing the value of the M-theory three-form potential. In holographic setups the choice of ensemble is important when comparing to observables in the dual field theory. Indeed, in AdS$_4$ holography the M2-ensemble does not map gravitational observables directly to field theory observables at a fixed rank $N$, but rather to observables in the grand canonical ensemble. We remark that many M2-brane partition functions take a simple form in this ensemble hinting at one-loop exactness. We also discuss how in AdS$_7$ holography, the M2-ensemble does correspond to the canonical ensemble in the field theory, i.e. the (2,0) theory at fixed rank $N$.

hep-th↗

arXiv2025

Wilson Loops and Spherical Branes

We study 1/2-BPS Wilson loop operators in maximally supersymmetric Yang-Mills theory on $d$-dimensional spheres. Their vacuum expectation values can be computed at large $N$ through supersymmetric localisation. The holographic duals are given by back-reacted spherical D-branes. For $d\neq 4$, the resulting theories are non-conformal and correspondingly, the dual geometries do not possess an asymptotic AdS region. The main aim of this work is to compute the holographic Wilson loops by evaluating the partition function of a probe fundamental string and M2-brane in the dual geometry, focusing on the next-to-leading order. Along the way, we highlight a variety of issues related to the presence of a non-constant dilaton. In particular, the structure of the divergences of the one-loop partition functions takes a non-universal form in contrast to examples available in the literature. We devise a general framework to treat the divergences, successfully match the sub-leading scaling with $λ$ and $N$, and provide a first step towards obtaining the numerical prefactor.

hep-th↗

arXiv2025

One-loop quantization of Euclidean D3-branes in holographic backgrounds

In this note we analyze the semi-classical quantization of D3 branes in three different holographic backgrounds in type IIB string theory. The first background is Euclidean AdS$_5$ with $S^1\times S^3$ boundary accompanied with a twist to preserve supersymmetry. We work out the spectrum of fluctuations around the classical D3-brane configuration, compute its one-loop partition function, and match to the non-perturbative correction to the superconformal index of ${\cal N}=4$ SYM. We then study Euclidean D3-branes in the Pilch-Warner geometry dual to the IR Leigh-Strassler fixed point of ${\cal N}=1^*$ with the aim to find non-perturbative corrections to its index. Finally we study Euclidean D3-branes in the non-geometric ${\cal N}=2$ J-fold background which is dual to the gauging of the 3D Gaiotto-Witten SCFT.

hep-th↗

arXiv2024

Spherical Branes and the BMN Matrix Quantum Mechanics

We study the maximally supersymmetric Yang-Mills theory on $S^d$ using supersymmetric localisation and holography. We argue that the analytic continuation in dimension to $d=1$ yields a Euclidean version of the BMN matrix quantum mechanics. This system can be analysed at large $N$ using supersymmetric localisation and leads to explicit results for the free energy on $S^d$ and the expectation value of supersymmetric Wilson loops. We show how these results can be reproduced at strong gauge coupling using holography by employing spherical D-brane solutions. We construct these solutions for any value of $d$ using an effective supergravity description and pay particular attention to the subtleties arising in the $d\to1$ limit. Our results have implications for the BMN matrix quantum mechanics and the physics of circular D0-branes.

hep-th↗

arXiv2024

The Conformal Manifold of S-folds in String Theory

We continue the holographic exploration of the conformal manifold of 3d $\mathcal{N}=2$ S-fold SCFTs constructed by gauging the flavor symmetry of the Gaiotto-Witten $T[U(N)]$ theory. We show how to uplift the two-parameter family of AdS$_4$ vacua dual to this conformal manifold to 10d backgrounds of type IIB supergravity. We use these uplifted solutions to shed new light on the mysterious nature of the infinite distance limit on the conformal manifold and to study probe strings and D3-branes. This analysis uncovers an intriguing structure of the $S^3$ partition function of the S-fold SCFTs which resembles the giant graviton expansion of the superconformal index of 4d $\mathcal{N}=4$ SYM. We also show how to each member of the family of supersymmetric AdS$_4$ vacua one can associate a consistent truncation to 4d $\mathcal{N}=2$ gauged supergravity and use this result, in conjunction with holography, to calculate the large $N$ partition function of the 3d S-fold SCFT on compact Euclidean manifolds. Finally, we generalize the supersymmetric AdS$_4$ vacua to a four-parameter family of non-supersymmetric AdS$_4$ solutions.

hep-th↗

arXiv2023

Quantized Strings and Instantons in Holography

We study worldsheet instantons in holographic type IIA backgrounds directly in string theory. The first background is a dimensional reduction of AdS$_7\times S^4$ and is dual to the maximally supersymmetric Yang-Mills theory on $S^5$. The second background is AdS$_4\times \mathbf{C}P^3$ dual to ABJM in the type IIA limit. We compute the one-loop partition function of the fundamental string in these backgrounds and show that the result is in exact agreement with field theory predictions. We argue that for higher rank instantons, the string partition function takes a product form of the single instanton partition function times the contribution of two orbifolds on the worldsheet. We determine the orbifold factor to be $n^{-3/2}$ where $n$ is the instanton rank. With this result, we reproduce the series of non-perturbative corrections in $α'$ to the planar $S^5$ free energy. When studying the worldsheet instanton partition function on $\mathbf{C}P^3$, we encounter twelve fermionic and twelve bosonic zero modes. By deforming the ABJM theory, the zero-modes are lifted and consequently the tower of worldsheet instantons can be evaluated and matched to known results in the QFT. As a by-product, we determine a series of higher rank instanton corrections to the free energy of the mass-deformed and orbifolded ABJ(M) theory.

hep-th↗

arXiv2023

Supersymmetric wormholes in String theory

We construct a large family of Euclidean supersymmetric wormhole solutions of type IIB supergravity which are asymptotically AdS$_5 \times S^5$. The solutions are constructed using consistent truncation to maximally gauged supergravity in five dimensions which is further truncated to a four scalar model. Within this model we perform a full analytic classification of supersymmetric domain wall solutions with flat Euclidean domain wall slices. On each side of the wormhole, the solution asymptotes to AdS$_5$ dual to ${\cal N}= 4$ supersymmetric Yang-Mills deformed by a supersymmetric mass term.

hep-th↗

arXiv2023

Holographic 3d $\mathcal N=1$ Conformal Manifolds

We construct and study several examples of continuous families of AdS$_4$ $\mathcal N = 1$ solutions of four-dimensional maximal gauged supergravity. These backgrounds provide the holographic descriptions of conformal manifolds of the dual 3d $\mathcal N = 1$ SCFTs. The solutions we study can be uplifted to type IIB supergravity where they arise from D3-branes wrapping an $S^1$ with an S-duality twist. We find the spectrum of low lying operators in the 3d $\mathcal N = 1$ SCFTs as a function of the exactly marginal coupling and discuss the structure of the corresponding superconformal multiplets. Using string theory techniques we also study additional examples of continuous families of $\mathcal N = 1$ AdS$_4$ vacua in type IIB and massive type IIA supergravity.

hep-th↗

arXiv2021

Comments on chiral algebras and $Ω$-deformations

Every six-dimensional $\mathcal{N}=(2,0)$ SCFT on $\mathbf{R}^6$ contains a set of protected operators whose correlation functions are controlled by a two-dimensional chiral algebra. We provide an alternative construction of this chiral algebra by performing an $Ω$-deformation~of a topological-holomorphic twist of the $\mathcal{N}=(2,0)$ theory on $\mathbf{R}^6$ and restricting to the cohomology of a specific supercharge. In addition, we show that the central charge of the chiral algebra can be obtained by performing equivariant integration of the anomaly polynomial of the six-dimensional theory. Furthermore, we generalize this construction to include orbifolds of the $\mathbf{R}^4$ transverse to the chiral algebra plane.

hep-th↗

arXiv2021

Marginal deformations from type IIA supergravity

We study marginal deformations of a class of three-dimensional $\mathcal{N}=2$ SCFTs that admit a holographic dual description in massive type IIA supergravity. We compute the dimension of the conformal manifold in these SCFTs and identify a special submanifold with enhanced flavor symmetry. We show how to apply the TsT transformation of Lunin-Maldacena to construct explicit supersymmetric AdS$_4$ solutions of massive type IIA supergravity with non-trivial internal fluxes that are the holographic dual of these marginal deformations. Finally, we also briefly comment on a class of RG flows between some of these SCFTs that also admit a holographic realization.

hep-th↗

arXiv2021

The Holographic Conformal Manifold of 3d $\mathcal{N}=2$ $S$-fold SCFTs

We employ a non-compact gauging of four-dimensional maximal supergravity to construct a two-parameter family of AdS$_4$ J-fold solutions preserving $\mathcal{N}=2$ supersymmetry. All solutions preserve $\mathfrak{u}(1)\times\mathfrak{u}(1)$ global symmetry and in special limits we recover the previously known $\mathfrak{su}(2)\times\mathfrak{u}(1)$ invariant $\mathcal{N}=2$ and $\mathfrak{su}(2)\times\mathfrak{su}(2)$ invariant $\mathcal{N}=4$ J-fold solutions. This family of AdS$_4$ backgrounds can be uplifted to type IIB string theory and is holographically dual to the conformal manifold of a class of three-dimensional $S$-fold SCFTs obtained from the $\mathcal{N}=4$ $T[\text{U}(N)]$ theory of Gaiotto-Witten. We find the spectrum of supergravity excitations of the AdS$_4$ solutions and use it to study how the operator spectrum of the three-dimensional SCFT depends on the exactly marginal couplings.

hep-th↗

arXiv2020

New AdS$_4$ Vacua in Dyonic ISO(7) Gauged Supergravity

We identify 219 AdS$_4$ solutions in four-dimensional dyonically gauged ISO(7) $\mathcal{N}=8$ supergravity and present some of their properties. One of the new solutions preserves $\mathcal{N}=1$ supersymmetry and provides a rare explicit example of an AdS$_4$ vacuum dual to a 3d SCFT with no continuous global symmetry. There are also two new non-supersymmetric solutions for which all 70 scalar fields in the supergravity theory have masses above the BF bound. All of these AdS$_4$ solutions can be uplifted to massive type IIA supergravity. Motivated by this we present the low lying operator spectra of the dual 3d CFTs for all known supersymmetric AdS$_4$ solutions in the theory and organize them into superconformal multiplets.

hep-th↗

arXiv2020

A Cornucopia of AdS$_5$ Vacua

We report on a systematic search for AdS$_5$ vacua corresponding to critical points of the potential in the five-dimensional $\mathcal{N}=8$ SO(6) gauged supergravity. By employing Google's TensorFlow Machine Learning library, we find the total of 32 critical points including 5 previously known ones. All 27 new critical points are non-supersymmetric. We compute the mass spectra of scalar fluctuatons for all points and find that the non-supersymmetric AdS$_5$ vacua are perturbatively unstable. Many of the new critical points can be found analytically within consistent truncations of the $\mathcal{N}=8$ supergravity with respect to discrete subgroups of the S(O(6)$\times$ GL(2,$\mathbb{R}$)) symmetry of the potential. In particular, we discuss in detail a $\mathbb{Z}_2^3$-invariant truncation with 10 scalar fields and 15 critical points. We also compute explicitly the scalar potential in a $\mathbb{Z}_2^2$-invariant extension of that truncation to 18 scalar fields and reproduce 17 of the 32 critical points from the numerical search. Finally, we show that the full potential as a function of 42 scalar fields can be studied analytically using the so-called solvable parametrization. In particular, we find that all critical points lie in a $\mathbb{Z}_2$-invariant subspace spanned by 22 scalar fields.

hep-th↗

arXiv2020

Janus and J-fold solutions in type IIB supergravity

I discuss recent supergravity constructions of type IIB holographic interfaces in four-dimensional ${\cal N}=1$ and ${\cal N}=4$ field theories. I explain how each holographic interface can be compactified on a circle with an SL$(2,{\bf Z})$ monodromy leading to a novel AdS$_4$ supergravity solution. These AdS$_4$ backgrounds are argued to be dual to so-called J-fold superconformal field theories in three dimensions.

hep-th↗

arXiv2020

Holographic Uniformization and Black Hole Attractors

We establish an attractor mechanism for the horizon metric of asymptotically locally AdS4 supersymmetric black holes. The Kähler moduli of the metric are not fixed in the asymptotic region, however supersymmetry dictates that the near horizon metric must be the constant curvature one. We show how this mechanism is realized in detail for four-dimensional N=2 gauged supergravity coupled to vector multiplets by focusing on the STU model. A similar analysis is performed for gauged supergravity theories in five, six, and seven dimensions where we establish the same mechanism by extending previous results on holographic uniformization.

hep-th↗