arXiv subjects

K. Koutrolikos

Publications and source records attributed to K. Koutrolikos.

9 recordsLinked to original sources

arXiv2022

Superspace BRST/BV operators of superfield gauge theories

We consider the superspace BRST and BV description of $4D,~\mathcal{N}=1$ Super Maxwell theory and its non-abelian generalization Super Yang-Mills. By fermionizing the superspace gauge transformation of the gauge superfields we define the nilpotent superspace BRST symmetry transformation ($\mathscr{s}$). After introducing an appropriate set of anti-superfields and define the superspace antibracket, we use it to construct the BV-BRST nilpotent differential operator ($\mathfrak{s}$) in terms of superspace covariant derivatives. The anti-superfield independent terms of $\mathfrak{s}$ provide a superspace generalization of the Koszul-Tate resolution ($δ$). In the linearized limit, the set of superspace differential operators that appear in $\mathfrak{s}$ satisfy a nonlinear algebra which can be used to construct a BRST charge $Q$ without requiring pure spinor variables. $Q$ acts on the Hilbert space of superfield states and its cohomology generates the expected superspace equations of motion.

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arXiv2021

Superspace First Order Formalism, Trivial Symmetries and Electromagnetic Interactions of Linearized Supergravity

We introduce a first order description of linearized non-minimal ($n=-1$) supergravity in superspace, using the unconstrained prepotential superfield instead of the conventionally constrained super one forms. In this description, after integrating out the connection-like auxiliary superfield of first-order formalism, the superspace action is expressed in terms of a single superfield which combines the prepotential and compensator superfields. We use this description to construct the supersymmetric cubic interaction vertex $3/2-3/2-1/2$ which describes the electromagnetic interaction between two non-minimal supergravity multiplets (superspin $\textsf{Y}=3/2$ which contains a spin 2 and a spin 3/2 particles) and a vector multiplet (superspin $\textsf{Y}=1/2$ contains a spin 1 and a spin 1/2 particles). Exploring the trivial symmetries emerging between the two $\textsf{Y}=3/2$ supermultiplets, we show that this cubic vertex must depend on the vector multiplet superfield strength. This result generalize previous results for non-supersymmetric electromagnetic interactions of spin 2 particles. The constructed cubic interaction generates non-trivial deformations of the gauge transformations.

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arXiv2020

Hierarchy of Supersymmetric Higher Spin Connections

We focus on the geometrical reformulation of free higher spin supermultiplets in $4\rm{D},~\mathcal{N}=1$ flat superspace. We find that there is a de Wit-Freedman like hierarchy of superconnections with simple gauge transformations. The requirement for sensible free equations of motion imposes constraints on the gauge parameter superfields. Unlike the nonsupersymmetric case, we find several different constraints that can decouple the higher superconnections. By lifting these constraints nongeometrically via compensators we recover all known descriptions of arbitrary integer and half-integer gauge supermultiplets. In the constrained formulation we find a new description of half-integer supermultiplets, generalizing the new-minimal and virial formulations of linearized supergravity to higher spins. However this description can be formulated using compensators. The various descriptions can be labeled as geometrical or nongeometrical if the equations of motion can be expressed purely in terms of superconnections or not.

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arXiv2019

Higher Spin Supersymmetry at the Cosmological Collider: Sculpting SUSY Rilles in the CMB

We study the imprint of higher spin supermultiplets on cosmological correlators, namely the non-Gaussianity of the cosmic microwave background. Supersymmetry is used as a guide to introduce the contribution of fermionic higher spin particles, which have been neglected thus far in the literature. This necessarily introduces more than just a single additional fermionic superpartner, since the spectrum of massive, higher spin supermultiplets includes two propagating higher spin bosons and two propagating higher spin fermions, which all contribute to the three point function. As an example we consider the half-integer superspin $\textsf{Y}=s+1/2$ supermultiplet, which includes particles of spin values $j=s+1,~j=s+1/2,~j=s+1/2$ and $j=s$. We compute the curvature perturbation 3-point function for higher spin particle exchange and find that the known $P_{s}(\cos θ)$ angular dependence is accompanied by superpartner contributions that scale as $P_{s+1}(\cos θ)$ and $\sum_{m}P^{m}_{s} (\cos θ)$, with $P_{s}$ and $P_{s} ^m$ defined as the Legendre and Associated Legendre polynomials respectively. We also compute the tensor-scalar-scalar 3-point function, and find a complicated angular dependence as an integral over products of Legendre and associated Legendre polynomials.

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arXiv2019

Progress on cubic interactions of arbitrary superspin supermultiplets via gauge invariant supercurrents

We consider cubic interactions of the form $s-Y-Y$ between a massless integer superspin $s$ supermultiplet and two massless arbitrary integer or half integer superspin $Y$ supermultiplets. We focus on non-minimal interactions generated by gauge invariant supercurrent multiplets which are bilinear in the superfield strength of the superspin $Y$ supermultiplet. We find two types of consistent supercurrents. The first one corresponds to conformal integer superspin $s$ supermultiplets, exist only for even values of $s, s=2\ell+2$, for arbitrary values of $Y$ and it is unique. The second one, corresponds to Poincaré integer superspin $s$ supermultiplets, exist for arbitrary values of $s$ and $Y$.

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arXiv2019

Integer superspin supercurrents of matter supermultiplets

In recent papers we demonstrated that consistent and non-trivial \emph{linear} transformations of matter supermultiplets generate half-integer superspin supercurrents and the cubic interactions between matter and half-integer superspin supermultiplets. In this work we show that consistent and non-trivial \emph{antilinear} transformations of matter superfields lead to the construction of integer superspin supercurrents and the cubic interactions between mater and integer superspin supermultiplets. Applying Noether's method to these transformations, we find new integer superspin supercurrents for the case of a free massless chiral superfield. Furthermore, we use them to find new integer superspin supercurrent multiplets for a massive chiral superfield and a chiral superfield with a linear superpotential. Also various selection rules for such interactions are found.

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arXiv2019

Superfield continuous spin equations of motion

We propose a description of %manifestly supersymmetric continuous spin representations in $4D,\mathcal{N}=1$ Minkowski superspace at the level of equations of motions. The usual continuous spin wave function is promoted to a chiral or a complex linear superfield which includes both the single-valued (span integer helicities) and the double-valued (span half-integer helicities) representations thus making their connection under supersymmetry manifest. The set of proposed superspace constraints for both superfield generate the expected Wigner's conditions for both representations.

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arXiv2017

Complex linear superfields, Supercurrents and Supergravities

We present expressions for the supercurrents generated by a generic $4D,~\mathcal{N}=1$ theory of complex linear superfield $Σ$. We verify that these expressions satisfy the appropriate superspace conservation equations. Furthermore, we discuss the component projection in order to derive expressions for the energy-momentum tensor, the supersymmetry current and the R-symmetry current when available. In addition, we discuss aspects of the coupling of the theory to supergravity. Specifically, we present a straightforward method to select the appropriate formulations of supergravity that one must use in order to do the coupling. This procedure is controlled by a superfield X originating from the Super-Poincaré invariance of the theory. We apply these results to examples of theories with higher derivative terms.

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arXiv2015

BRST Analysis of the Supersymmetric Higher Spin Field Models

We develop the BRST approach for all massless integer and half-integer higher spins in 4D Minkowski space, using the two component spinor nota- tion and develop the Lagrangian formulation for supersymmetric higher spin models. It is shown that the problem of second class constraints disappears and the BRST procedure becomes much more simple than in tensorial nota- tion. Furthermore, we demonstrate that the BRST procedure automatically provides extra auxiliary components that belong in the set of supersymmetry auxiliary components. Finally, we demonstrate how supersymmetry transfo- rmations are realized in such an approach. As a result, we conclude that the BRST approach to higher spin supersymmetric theories allows to derive both the Lagrangian and the supersymmetry transformations. Although most part of the work is devoted to massless component supersymmetric models, we also discuss generalization for massive component supersymmetric models and for superfield models.

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