arXiv subjects

Soumya Adhikari

Publications and source records attributed to Soumya Adhikari.

9 recordsLinked to original sources

arXiv2026

Boundary-Value Problem in Type IIB Supergravity and Holography

In precision holography, the Euclidean on-shell action of type IIB supergravity often fails to reproduce the leading large-$N$ free energy of the dual field theory: the type IIB pseudo action, for instance, vanishes identically on the $\mathrm{EAdS}_5\times S^5$ background. We address this issue by revisiting the boundary-value problem of the Euclidean type IIB pseudo action from first principles. Classifying the admissible boundary conditions through the variational principle, we construct a generalized pseudo action whose boundary terms implement the choice of ensemble --- fixed potentials versus fixed quantized Page charges --- in which the holographic comparison is performed. For the fixed five-form-charge ensemble, the resulting boundary term reproduces the recently proposed topological correction to the Pasti--Sorokin--Tonin formulation of type IIB supergravity for holographic backgrounds of interest. We then test the generalized pseudo action on two complementary backgrounds: the $\mathrm{EAdS}_3\times S^3\times M_4$ near-horizon geometry of the D1-D5 system and the warped $\mathrm{EAdS}_6\times S^2\timesΣ$ solutions dual to five-dimensional SCFTs. In both cases the ten-dimensional on-shell action agrees exactly with that of the corresponding lower-dimensional supergravity, and thereby with the leading large-$N$ free energy of the dual SCFT. Our results establish the choice of boundary conditions --- and hence of ensemble --- as an essential ingredient of precision holography directly in type IIB supergravity, extending recent analyses in eleven-dimensional supergravity.

hep-th↗

arXiv2026

Type IIB Supergravity Action and Holography

In the prototypical AdS$_5$/CFT$_4$ correspondence, the free energy of $\mathcal{N}=4$ SU$(N)$ super Yang-Mills theory is commonly reproduced from the Euclidean on-shell action of five-dimensional gauged supergravity -- a consistent truncation of Type IIB supergravity -- rather than computed directly in ten dimensions. A longstanding obstacle to the latter is that the conventional Type IIB pseudo-action evaluated on the $AdS_5\times S^5$ background vanishes identically, apparently precluding a first-principles holographic comparison. A recent proposal by Kurlyand and Tseytlin, based on the Pasti-Sorokin-Tonin formulation, resolves this issue for a special class of backgrounds including the $AdS_5\times S^5$ vacuum by introducing a topological term required for consistency, yielding a non-vanishing on-shell value in agreement with holography. In this work we extend this refinement to a broader class of Type IIB backgrounds by introducing a generalized topological correction under milder conditions, encompassing AdS geometries of generic dimension and non-vanishing 2-form potentials. We test the proposal on non-trivial solutions such as the Lunin-Maldacena background and the $AdS_4$ $S$-fold solution, and find agreement with the corresponding lower-dimensional gauged supergravity on-shell actions and thereby with the expected holographic observables. Our results place direct holographic comparisons within the ten-dimensional Type IIB framework on firmer ground.

hep-th↗

arXiv2026

Attractor saddle for 5D black hole index

In a recent paper, Anupam, Chowdhury, and Sen [arXiv:2308.00038] constructed the non-extremal saddle that reproduces the supersymmetric index of the BMPV black hole with three independent charges in the classical limit. This saddle solution is a finite temperature complex solution saturating the BPS bound. In this paper, we write this solution in a canonical form in terms of harmonic functions on three-dimensional flat base space, thereby showing that it is supersymmetric. We also show that it exhibits the new form of attraction.

hep-th↗

arXiv2026

BPS Solutions of 4d Euclidean N=2 Supergravity with Higher Derivative Interactions

We study fully BPS and a broad class of half-BPS stationary configurations of four-dimensional Euclidean N=2 supergravity with higher-derivative interactions. Working within the off-shell conformal supergravity framework of de Wit and Reys (arXiv:1706.04973), we analyse the complete set of Killing spinor equations and obtain the corresponding algebraic and differential constraints. We further derive the Euclidean attractor equations and evaluate the Wald entropy for the fully BPS AdS_2 x S^2 background. For half-BPS stationary configurations, we obtain the generalized stabilization equations expressing all fields in terms of harmonic functions on three-dimensional flat base space, extending the Lorentzian analysis of Cardoso et al (arXiv:hep-th/0009234) to the Euclidean signature. Our results provide a framework for studying supersymmetric saddles and computing the gravitational indices entirely within Euclidean higher-derivative supergravity, without recourse to analytic continuation.

hep-th↗

arXiv2025

Supersymmetric truncation of N=3 dilaton Weyl multiplet

We perform all possible supersymmetric truncations of the four-dimensional N=3 dilaton Weyl multiplet, which realizes an R-symmetry $SU(2) \times U(1) \times U(1)$, to N=2. A particular truncation procedure does not break any of the R-symmetries and leads to the known N=2 vector-dilaton Weyl multiplet and the N=2 vector multiplet. A different truncation procedure breaks the SU(2) part of the R-symmetry to U(1) and leads to a 32+32 off-shell representation of N=2 conformal supergravity with a partially broken R-symmetry. Independently, we construct another 32+32 off-shell multiplet in N=2 conformal supergravity by coupling the N=2 scalar-tensor multiplet to the N=2 standard Weyl multiplet and using the scalar fields present in the scalar-tensor multiplet to break the SU(2) R-symmetry to U(1). We then establish the equivalence between these two multiplets through a mapping. We observe that this 32+32 multiplet is gauge equivalent to a Poincaré supergravity multiplet as it has all the compensators necessary to go from conformal supergravity to Poincaré supergravity.

hep-th↗

arXiv2025

Dilaton Weyl multiplets for $N = 3$ conformal supergravity in four dimensions

We construct a dilaton Weyl multiplet for $N = 3$ conformal supergravity in four dimensions. We couple an on-shell vector multiplet to the standard Weyl multiplet and use the field equations of the vector multiplet to replace some of the components of the auxiliary fields of the standard Weyl multiplet with the fields of the vector multiplet and some dual gauge fields. The R-symmetry of the multiplet is $SU(2) \times U(1) \times U(1)$. Furthermore, we gauge fix one of the two $U(1)$ symmetries and rewrite the result for the dilaton Weyl multiplet with $SU(2) \times U(1)$ R-symmetry.

hep-th↗

arXiv2025

Variant dilaton Weyl Multiplet for N=3 conformal supergravity in four dimensions

We construct a new dilaton Weyl multiplet for $\mathcal{N}=3$ conformal supergravity in four dimensions. The R-symmetry realized on this dilaton Weyl multiplet is $SU(2) \times U(1) \times U(1)$. The construction follows a two-step procedure. Firstly, two on-shell vector multiplets are coupled to the standard Weyl multiplet. Secondly, using the field equations of the vector multiplets, some of the auxiliary fields of the standard Weyl multiplet are solved in terms of the fields belonging to the vector multiplets and some dual gauge fields. The remaining fields of the standard Weyl multiplet combine with the vector multiplet fields and the dual gauge fields to constitute the new dilaton Weyl multiplet.

hep-th↗

arXiv2025

$SU(2)\times SU(2)$ dilaton Weyl multiplets for maximal conformal supergravity in four, five, and six dimensions

New dilaton Weyl multiplets are constructed in four and five space-time dimensions for $N=4$ and $N=2$ conformal supergravity respectively. They are constructed from a mixture of the old dilaton weyl multiplets with an on-shell vector multiplet. The old dilaton Weyl multiplets have a $USp(4)$ R-symmetry group whereas the new multiplets have $SU(2)\times SU(2)$ R-symmetry, which is a subgroup of $USp(4)$. In six dimensions, for the first time we construct a dilaton Weyl multiplet for $(2,0)$ conformal supergravity from a mixture of the standard Weyl multiplet and a tensor multiplet. The R-symmetry group for the dilaton Weyl multiplet in six dimensions is also $SU(2)\times SU(2)$.

hep-th↗

arXiv2024

N=2 conformal supergravity in five dimensions

N=2 conformal supergravity in five dimensions is constructed via a systematic off-shell reduction scheme from maximal conformal supergravity in six dimensions which is (2,0). The dimensional reduction of the (2,0) Weyl multiplet in six dimensions gives us the Weyl multiplet in five dimensions which is a dilaton Weyl multiplet as it has a dilaton scalar. The dimensional reduction of the (2,0) tensor multiplet in six dimensions gives us the N=2 vector multiplet in five dimensions coupled to conformal supergravity. We also comment on Nahm's classification regarding the non-existence of an N=2 superconformal algebra in five dimensions and why it does not contradict the existence of N=2 conformal supergravity in five dimensions that is constructed in this paper.

hep-th↗