arXiv subjects

Christoph F. Uhlemann

Publications and source records attributed to Christoph F. Uhlemann.

At least 37 records · Page 2Linked to original sources

arXiv2021

On the planar limit of 3d $T_ρ^σ[SU(N)]$

We discuss a limit of 3d $T_ρ^σ[SU(N)]$ quiver gauge theories in which the number of nodes is large and the ranks scale quadratically with the length of the quiver. The sphere free energies and topologically twisted indices are obtained using supersymmetric localization. Both scale quartically with the length of the quiver and quadratically with $N$, with trilogarithm functions depending on the quiver data as coefficients. The IR SCFTs have well-behaved supergravity duals in Type IIB, and the free energies match precisely with holographic results. Previously discussed theories with $N^2\ln N$ scaling arise as limiting cases. Each balanced 3d quiver theory is linked to a 5d parent, whose matrix model is related and dominated by the same saddle point, leading to close relations between BPS observables.

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arXiv2021

Evidence for a 5d F-theorem

Renormalization group flows are studied between 5d SCFTs engineered by $(p,q)$ 5-brane webs with large numbers of external 5-branes. A general expression for the free energy on $S^5$ in terms of single-valued trilogarithm functions is derived from their supergravity duals, which are characterized by the 5-brane charges and additional geometric parameters. The additional geometric parameters are fixed by regularity conditions, and we show that the solutions to the regularity conditions extremize a trial free energy. These results are used to survey a large sample of $\mathcal O(10^5)$ renormalization group flows between different 5d SCFTs, including Higgs branch flows and flows that preserve the $SU(2)$ $R$-symmetry. In all cases the free energy changes monotonically towards the infrared, in line with a 5d $F$-theorem.

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arXiv2021

Surface defects in holographic 5d SCFTs

We use holography to study codimension-2 surface defects in 5d SCFTs engineered by $(p,q)$ 5-brane webs. The three-dimensional defects are realized by D3-branes ending on the brane web. We identify the holographic representation of the defects in Type IIB $AdS_6$ solutions as probe D3-branes, and study conformal and non-conformal defects which, respectively, preserve one half and one quarter of the supersymmetry. For a sample of 5d SCFTs, including the $T_N$ theories, we provide explicit solutions for conformal and non-conformal defects. For the conformal defects we obtain their contribution to the free energy on $S^5$.

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arXiv2020

Janus on the Brane

We present a non-supersymmetric deformation of probe branes describing conformal defects of codimension two in AdS/CFT. The worldvolume of the probe branes is deformed from $AdS_{p}\times S^1$ embedded in an $AdS_{p+2} \times \mathcal M^{D-p-2}$ background to an embedding of Janus form, which uses an $AdS_{p-1}$ slicing of $AdS_p$ and in which the brane bends along the slicing coordinate. In field theory terms this realizes conformal interfaces on codimension-two defects. We discuss these "Janus on the brane" solutions for $AdS_3\times S^1$ D3-branes in the $AdS_5\times S^5$ solution of Type IIB, realizing interfaces on surface defects in $\mathcal N=4$ SYM, and show that similar solutions exist for probe branes in $AdS_{p+2}\times S^{9-p}$ vacua of M-theory and in the $AdS_6\times S^4$ solution of massive Type IIA.

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arXiv2020

Wilson loops in 5d long quiver gauge theories

Quiver gauge theories with a large number of nodes host a wealth of Wilson loop operators. Expectation values are obtained, using supersymmetric localization, for Wilson loops in the antisymmetric representations associated with each individual gauge node, for a sample of 5d long quiver gauge theories whose UV fixed points have holographic duals in Type IIB. The sample includes the $T_N$ theories and the results are uniformly given in terms of Bloch-Wigner functions. The holographic representation of the Wilson loops is identified. It comprises, for each supergravity solution, a two-parameter family of D3-branes which exactly reproduce the field theory results and identify points in the internal space with the faces of the associated 5-brane web. The expectation values of (anti)fundamental Wilson loops exhibit an enhanced scaling for many operators, which matches between field theory and supergravity.

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arXiv2019

AdS$_6$/CFT$_5$ with O7-planes

Type IIB AdS$_6$ solutions with orientifold 7-planes are constructed. The geometry is a warped product of AdS$_6$ and S$^2$ over a Riemann surface $Σ$ and the O7-planes correspond to a particular type of puncture on $Σ$. The solutions are identified as near-horizon limits of $(p,q)$ 5-brane webs with O7-planes. The dual 5d SCFTs have relevant deformations to linear quiver gauge theories which have $SO(\cdot)$ or $USp(\cdot)$ nodes or $SU(\cdot)$ nodes with hypermultiplets in symmetric or antisymmetric representations, in addition to $SU(\cdot)$ nodes with fundamental hypermultiplets. The S$^5$ free energies are obtained holographically and matched to field theory computations using supersymmetric localization to support the proposed dualities.

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arXiv2019

Exact results for 5d SCFTs of long quiver type

Exact results are derived for 5d SCFTs with holographic duals in Type IIB supergravity. These theories have relevant deformations that flow to linear quiver gauge theories, with the number of nodes large in the large-$N$ limits described by supergravity. Starting from a suitable formulation of the matrix models resulting from supersymmetric localization of the squashed $S^5$ partition functions, the saddle point equations are solved for generic quivers with $N_f=2N$ at all interior nodes, which includes the $T_N$ theories, and for a sample of theories with $N_f\neq 2N$ nodes including theories with Chern-Simons terms. The resulting exact expressions for the free energies and conformal central charges are consistent with supergravity predictions and, where available, with previous numerical field theory analyses.

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arXiv2019

Black hole microstate counting in Type IIB from 5d SCFTs

We use recently established AdS$_6$/CFT$_5$ dualities to count the microstates of magnetically charged AdS$_6 \times S^2 \times Σ$ black holes in Type IIB. The near-horizon limit is described by solutions with AdS$_2 \times Σ_{\mathfrak{g}_1} \times Σ_{\mathfrak{g}_2} \times S^2 \times Σ$ geometry, where $Σ_{\mathfrak{g}_i}$ are Riemann surfaces of constant curvature and $Σ$ is a further Riemann surface over which the geometry is warped. Our results show that the topologically twisted indices of the proposed dual superconformal field theories precisely reproduce the Bekenstein-Hawking entropy of this class of black holes. This provides further support for a prescription to compute five-dimensional topologically twisted indices put forth recently, and for the proposed dualities. We confirm the $N^4$ scaling found in the sphere partition functions and extend previous matches of sphere partition functions to AdS$_6$ solutions with monodromy.

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arXiv2019

Spin 2 operators in holographic 4d $\mathcal N=2$ SCFTs

A broad class of holographic duals for 4d $\mathcal N=2$ SCFTs is based on the general half-BPS $AdS_5$ solutions to M-theory constructed by Lin, Lunin and Maldacena, and their Kaluza-Klein reductions to Type IIA. We derive the equations governing spin 2 fluctuations around these solutions. The resulting partial differential equations admit families of universal solutions which are constructed entirely out of the generic data characterizing the background. This implies the existence of families of spin 2 operators in the dual SCFTs, in short superconformal multiplets which we identify.

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arXiv2019

Global half-BPS $AdS_2\times S^6$ solutions in Type IIB

We investigate half-BPS Type IIB supergravity solutions with spacetime geometry $AdS_2\times S^6$ warped over a Riemann surface $Σ$. The general local solution was obtained in earlier work in terms of two holomorphic functions $\mathcal A_\pm$ on $Σ$. In the first part of this paper we seek global solutions corresponding to the near-horizon behavior of $(p,q)$-string junctions. We identify the type of singularity in $\mathcal A_\pm$ needed at the boundary of $Σ$ to match the solutions locally onto the classic $(p,q)$-string solution. We construct solutions with multiple $(p,q)$-strings, but the existence of geodesically complete solutions remains unsettled. In a second part we construct multi-parameter families of non-compact globally regular and geodesically complete solutions with asymptotic regions and an $AdS_2$ throat which caps off smoothly.

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arXiv2018

On minimal Type IIB $AdS_6$ solutions with commuting 7-branes

We construct Type IIB supergravity solutions with geometry $AdS_6\times S^2$ warped over a disc with two boundary points where 5-branes emerge and punctures with 7-brane monodromy. They describe $(p,q)$ 5-brane junctions with two groups of like-charged external 5-branes that are unconstrained by the $s$-rule and an additional group of constrained 5-branes. The dual 5d SCFTs include various theories discussed previously in the literature. We match SCFT operators with scaling dimension of $\mathcal O(N)$ with their representation in supergravity to support the proposed dualities.

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arXiv2018

M-theory curves from warped AdS$_6$ in Type IIB

We establish a close relation between recently constructed AdS$_6$ solutions in Type IIB supergravity, which describe the near-horizon limit of $(p,q)$ 5-brane junctions, and the curves wrapped by M5-branes in the M-theory realization of the 5-brane junctions. This provides a geometric interpretation of various objects appearing in the construction of the Type IIB solutions and a physical interpretation of the regularity conditions. Conversely, the Type IIB solutions provide explicit solutions to the equations defining the M-theory curves associated with $(p,q)$ 5-brane junctions.

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arXiv2018

Massive spin 2 excitations in $AdS_6\times S^2$ warped spacetimes

We study (massive) spin-2 fluctuations around warped $AdS_6$ solutions with $16$ supersymmetries in type IIB supergravity. We identify two classes of fluctuations which are universally present for all solutions of this form. The holographically dual operators have scaling dimensions $Δ=5+3\ell$ and $Δ=6+3\ell$, where the integer $\ell$ encodes the $R$-symmetry charge. They are identified as descendant states in respective BPS multiplets (the current multiplet for $Δ=5$). We also compute the normalization of the energy-momentum tensor two-point function and show that it is related to the $S^5$ partition function of the dual $5d$ SCFTs.

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arXiv2018

Precision test of AdS$_6$/CFT$_5$ in Type IIB

Large classes of warped AdS$_6$ solutions were constructed recently in Type IIB supergravity, and identified as holographic duals for five-dimensional superconformal field theories realized by $(p,q)$ five-brane webs. We confront holographic results for the five sphere partition functions obtained from these solutions with computations for the putative dual field theories. We obtain the sphere partition functions and conformal central charges in gauge theory deformations of the superconformal field theories numerically using supersymmetric localization, and extrapolate the results to the conformal fixed points. In the appropriate large $N$ limits, the results match precisely to the supergravity computations, providing strong support for the proposed dualities.

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arXiv2018

Testing $AdS_6/CFT_5$ in Type IIB with stringy operators

We provide further evidence that the recently constructed warped $AdS_6$ solutions in Type IIB supergravity are dual to 5d SCFTs that correspond to $(p,q)$ 5-brane webs with large numbers of like-charged external 5-branes. We study a number of specific examples, including the $T_N$ theory, and identify the bulk states dual to a class of operators with ${\cal O}(N)$ scaling dimensions in terms of strings and string-webs embedded in the solutions.

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arXiv2018

Type IIB 7-branes in warped $AdS_6$: partition functions, brane webs and probe limit

We study Type IIB supergravity solutions with spacetime of the form $AdS_6\times S^2$ warped over a Riemann surface $Σ$, where $Σ$ includes punctures around which the supergravity fields have non-trivial $SL(2,R)$ monodromy. Solutions without monodromy have a compelling interpretation as near-horizon limits of $(p,q)$ 5-brane webs, and the punctures have been interpreted as additional 7-branes in the web. In this work we provide further support for this interpretation and clarify several aspects of the identification of the supergravity solutions with brane webs. To further support the identification of the punctures with 7-branes, we show that punctures with infinitesimal monodromy match a probe 7-brane analysis using $κ$-symmetry. We then construct families of solutions with fixed 5-brane charges and punctures with finite monodromy, corresponding to fully backreacted 7-branes. We compute the sphere partition functions of the dual 5d SCFTs and use the results to discuss concrete brane web interpretations of the supergravity solutions.

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arXiv2018

Warped $AdS_6\times S^2$ in Type IIB supergravity II: Global solutions and five-brane webs

Motivated by the construction of holographic duals to five-dimensional superconformal quantum field theories, we obtain global solutions to Type IIB supergravity invariant under the superalgebra $F(4)$ on a space-time of the form $AdS_6 \times S^2$ warped over a two-dimensional Riemann surface $Σ$. In earlier work, the general local solutions were expressed in terms of two locally holomorphic functions $\mathcal A_\pm$ on $Σ$ and global solutions were sketched when $Σ$ is a disk. In the present paper, the physical regularity conditions on the supergravity fields required for global solutions are implemented on $\mathcal A_\pm$ for arbitrary $Σ$. Global solutions exist only when $Σ$ has a non-empty boundary $\partial Σ$. The differentials $\partial \mathcal A_\pm$ are allowed to have poles only on $\partial Σ$ and each pole corresponds to a semi-infinite $(p,q)$ five-brane. The construction for the disk is carried out in detail and the conditions for the existence of global solutions are articulated for surfaces with more than one boundary and higher genus.

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arXiv2018

Holographic duals for five-dimensional superconformal quantum field theories

We construct global solutions to Type IIB supergravity with 16 residual supersymmetries whose space-time is $AdS_6 \times S^2$ warped over a Riemann surface. Families of solutions are labeled by an arbitrary number $L\geq 3$ of asymptotic regions, in each of which the supergravity fields match those of a $(p,q)$ five-brane, and may therefore be viewed as near-horizon limits of fully localized intersections of five-branes in Type IIB string theory. These solutions provide compelling candidates for holographic duals to a large class of five-dimensional superconformal quantum field theories which arise as non-trivial UV fixed points of perturbatively non-renormalizable Yang-Mills theories, thereby making them more directly accessible to quantitative analysis.

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