More Like this

1. Extended JT supergravity and random matrix models: The power of the string equation

   https://doi.org/10.1007/JHEP03(2026)126  

   Johnson, Clifford V; Kolanowski, Maciej (March 2026, Journal of High Energy Physics)

   A<sc>bstract</sc> A number of supersymmetric Jackiw-Teitelboim (JT) gravity theories are known to be described (in the Euclidean path integral formulation) by double-scaled random matrix models. Such matrix models can be characterized using a certain “string equation”. It was shown recently that in extended supergravity, when the number of BPS states scales as$$ {\textrm{e}}^{S_0} $$ $e^{S_0}$ , whereS₀is the extremal entropy, a special ansatz for the leading order solution of the string equation yields the supergravity spectrum. Somewhat miraculously, the construction showed that the functional form of the non-BPS (continuum) sector predicts the precise form of the BPS sector, showing the robustness of the supergravity/matrix-model correspondence. In this paper, we refine the analysis and show that the string equation, combined with some simple requirements on solutions, are powerful tools for constraining the spectrum of extended JT supergravity theories. We re-explore the cases of$$ \mathcal{N}=2 $$ $N=2$ and (small)$$ \mathcal{N}=4 $$ $N=4$ JT supergravity, and then explore the new cases of spectra from$$ \mathcal{N}=3 $$ $N=3$ and large$$ \mathcal{N}=4 $$ $N=4$ JT supergravity (recently derived by Heydeman, Shi, and Turiaci) showing that our approach also works naturally for (nearly) all the models. Based on this success, we conjecture that these new supergravity models also have matrix model descriptions. 

   more » « less
2. Deformation of d = 4, $$ \mathcal{N} $$ ≥ 5 supergravities breaks nonlinear local supersymmetry

   https://doi.org/10.1007/JHEP06(2023)156  

   Kallosh, Renata; Yamada, Yusuke (June 2023, Journal of High Energy Physics)

   A<sc>bstract</sc> We studyd= 4,$$ \mathcal{N} $$ $N$ ≥ 5 supergravities and their deformation via candidate counterterms, with the purpose to absorb UV divergences. We generalize the earlier studies of deformation and twisted self-duality constraint to the case with unbroken local$$ \mathcal{H} $$ $H$ -symmetry in presence of fermions. We find that the deformed action breaks nonlinear local supersymmetry. We show that all known cases of enhanced UV divergence cancellations are explained by nonlinear local supersymmetry. This result implies, in particular, that if$$ \mathcal{N} $$ $N$ = 5 supergravity at five loop will turn out to be UV divergent, the deformed theory will be BRST inconsistent. If it will be finite, it will be a consequence of nonlinear local supersymmetry and E7-type duality. 

   more » « less
3. Topologically charged BPS microstates in AdS3/CFT2

   https://doi.org/10.1007/JHEP03(2025)069  

   Ardehali, Arash Arabi; Krishna, Hare (March 2025, Journal of High Energy Physics)

   A<sc>bstract</sc> In the standard$$ \mathcal{N} $$ $N$ = (4, 4) AdS₃/CFT₂with sym^N(T⁴), as well as the$$ \mathcal{N} $$ $N$ = (2, 2) Datta-Eberhardt-Gaberdiel variant with sym^N(T⁴/ℤ₂), supersymmetric index techniques have not been applied so far to the CFT states with target-space momentum or winding. We clarify that the difficulty lies in a central extension of the SUSY algebra in the momentum and winding sectors, analogous to the central extension on the Coulomb branch of 4d$$ \mathcal{N} $$ $N$ = 2 gauge theories. We define modified helicity-trace indices tailored to the momentum and winding sectors, and use them for microstate counting of the corresponding bulk black holes. In the$$ \mathcal{N} $$ $N$ = (4, 4) case we reproduce the microstate matching of Larsen and Martinec. In the$$ \mathcal{N} $$ $N$ = (2, 2) case we resolve a previous mismatch with the Bekenstein-Hawking formula encountered in the topologically trivial sector by going to certain winding sectors. 

   more » « less
4. Consistent subsectors of maximal supergravity and wrapped M5-branes

   https://doi.org/10.1007/JHEP05(2026)003  

   Pico, Martín; Varela, Oscar (May 2026, Journal of High Energy Physics)

   A<sc>bstract</sc> A new family ofD= 4$$ \mathcal{N}=8 $$ $N=8$ gauged supergravities is introduced, consisting in a mixture of Scherk-Schwarz and dyonic CSO gaugings that involves the trombone scaling symmetry. A specific theory in this class is shown to admit supersymmetric anti-de Sitter vacua, argued to be related to various wrapped M5-brane configurations. The mass spectrum of these vacua within our maximal theory is computed, extending previous results in smaller gauged supergravity models, and shown to exhibit some exotic features due to the trombone gauging. These vacua are obtained as solutions of certain subsectors of our$$ \mathcal{N}=8 $$ $N=8$ supergravity. Such subsectors in turn arise by consistent truncation of the parent maximal supergravity to the invariant fields under specific groups that are not contained in the$$ \mathcal{N}=8 $$ $N=8$ gauge group. Prompted by these and other similar subtruncations recently considered, we formalise sufficient conditions that allow any maximal supergravity to be truncated consistently to invariant subsectors thereof when the invariance group is not necessarily contained in the$$ \mathcal{N}=8 $$ $N=8$ gauge group. 

   more » « less
5. When left and right disagree: entropy and von Neumann algebras in quantum gravity with general AlAdS boundary conditions

   https://doi.org/10.1007/JHEP08(2024)010  

   Marolf, Donald; Zhang, Daiming (August 2024, Journal of High Energy Physics)

   A<sc>bstract</sc> Euclidean path integrals for UV-completions ofd-dimensional bulk quantum gravity were recently studied in [1] by assuming that they satisfy axioms of finiteness, reality, continuity, reflection-positivity, and factorization. Sectors$$ {\mathcal{H}}_{\mathcal{B}} $$ $H_B$ of the resulting Hilbert space were then defined for any (d− 2)-dimensional surface$$ \mathcal{B} $$ $B$ , where$$ \mathcal{B} $$ $B$ may be thought of as the boundary ∂Σ of a bulk Cauchy surface in a corresponding Lorentzian description, and where$$ \mathcal{B} $$ $B$ includes the specification of appropriate boundary conditions for bulk fields. Cases where$$ \mathcal{B} $$ $B$ was the disjoint unionB⊔Bof two identical (d− 2)-dimensional surfacesBwere studied in detail and, after the inclusion of finite-dimensional ‘hidden sectors,’ were shown to provide a Hilbert space interpretation of the associated Ryu-Takayanagi entropy. The analysis was performed by constructing type-I von Neumann algebras$$ {\mathcal{A}}_L^B $$ $A_L^B$ ,$$ {\mathcal{A}}_R^B $$ $A_R^B$ that act respectively at the left and right copy ofBinB⊔B. Below, we consider the case of general$$ \mathcal{B} $$ $B$ , and in particular for$$ \mathcal{B} $$ $B$ =B_L⊔B_RwithB_L,B_Rdistinct. For anyB_R, we find that the von Neumann algebra atB_Lacting on the off-diagonal Hilbert space sector$$ {\mathcal{H}}_{B_L\bigsqcup {B}_R} $$ $H_{B_L\bigsqcup B_R}$ is a central projection of the corresponding type-I von Neumann algebra on the ‘diagonal’ Hilbert space$$ {\mathcal{H}}_{B_L\bigsqcup {B}_L} $$ $H_{B_L\bigsqcup B_L}$ . As a result, the von Neumann algebras$$ {\mathcal{A}}_L^{B_L} $$ $A_L^{B_L}$ ,$$ {\mathcal{A}}_R^{B_L} $$ $A_R^{B_L}$ defined in [1] using the diagonal Hilbert space$$ {\mathcal{H}}_{B_L\bigsqcup {B}_L} $$ $H_{B_L\bigsqcup B_L}$ turn out to coincide precisely with the analogous algebras defined using the full Hilbert space of the theory (including all sectors$$ {\mathcal{H}}_{\mathcal{B}} $$ $H_B$ ). A second implication is that, for any$$ {\mathcal{H}}_{B_L\bigsqcup {B}_R} $$ $H_{B_L\bigsqcup B_R}$ , including the same hidden sectors as in the diagonal case again provides a Hilbert space interpretation of the Ryu-Takayanagi entropy. We also show the above central projections to satisfy consistency conditions that lead to a universal central algebra relevant to all choices ofB_LandB_R. 

   more » « less