Research Projects

"Curvature squared action in four dimensional N = 2 supergravity using the dilaton Weyl multiplet."

M. Mishra and B. Sahoo

[JHEP04(2021)027]

"N = 3 Conformal Supergravity in Four Dimensions"

S, Hegde, M. Mishra and B. Sahoo

[JHEP04(2022)001]

“Thermodynamics of BPS and Near-BPS AdS6 Black Holes.”

M.Mishra and A. Virmani

[JHEP06(2022)087]

"Higher derivative invariants in four dimensional 𝒩 = 3 Poincaré supergravity

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S. Hegde, M. Mishra, D. Mukherjee and B. Sahoo,

[JHEP02(2023)145]

Curvature squared action in four-dimensional N=2 supergravity using the dilaton Weyl multiplet.

In this paper, we derive the most general curvature squared action coupled to an arbitrary number of vector multiplets in four-dimensional N = 2 supergravity using the dilaton Weyl multiplet. The action that we derive is encoded in a single holomorphic prepotential.

Thermodynamics of BPS and Near-BPS AdS6 Black Holes

N = 3 Conformal Supergravity in Four Dimensions

In this paper we derive the action for N = 3 conformal supergravity in four space-time dimensions. We construct a density formula for N = 3 conformal supergravity based on the superform action principle. Finally, we embed the N = 3 Weyl multiplet in the density formula to obtain the invariant action for N = 3 conformal supergravity. There are two inequivalent embeddings by changing a particular coefficient from real to imaginary. They lead to invariant actions, which will either be the supersymmetrization of the Weyl square term or the Pontryagin density in the eventuality of gauge fixing to Poincaré supergravity. As a consistency check of our formalism, we will show that the supersymmetrization of the Pontryagin density is a total derivative. We will demonstrate this for purely bosonic terms. We will also present the complete action for the supersymmetrization of Weyl square term. We also discuss consistent truncation of N = 4 Weyl multiplet to N = 3 Weyl multiplet and use it for a robust check of our results using the earlier known results in N = 4 conformal supergravity.

We develop the thermodynamics of BPS and near-BPS AdS6 black holes. We study the phase diagram of BPS black holes in the grand canonical ensemble. We highlight two distinct deformations orthogonal to the BPS surface: (i) increasing the temperature while keeping the charges fixed, (ii) changing the charges while maintaining extremality such that the BPS constraint is no longer satisfied. For both these deformations, we show that the considerations of the BPS entropy function can be extended to describe the near-BPS regime. The excess entropy together with changes in all potentials are perfectly accounted for via the extremization principle.

N = 3 Poincare Supergravity in Four Dimensions

In this paper, we use the superconformal approach to derive the action for N = 3 Poincare supergravity in four space-time dimensions. We first study the coupling of N = 3 vector multiplets to conformal supergravity. Thereafter we combine it with the pure N = 3 conformal supergravity action and use a minimum of three vector multiplets as compensators to arrive at Poincare supergravity with higher derivative corrections. We give a general prescription on how to eliminate the auxiliary fields in an iterative manner and obtain the supergravity action order by order in derivatives. We also show that the truncation of the action at fourth order in derivatives is a consistent truncation.