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Gustavsson Andreas | Gustavsson Simon | Gustavsson K. | Gustavsson S. | Gustavsson Ulf | Gustavsson Mattias | Gustavsson Kristian | Gustavsson Emil | Gustavsson C. | Gustavsson Anna C. T.

Andreas Jacob | Andreas Bjorn | Andreas Sarah | Andreas B. | Andreas S. | Andreas Christian | Andreas Edgar L | Andreas Stefan | Andreas Bjoern | Andreas C.

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A nonabelian M5 brane Lagrangian in a supergravity background

Gustavsson Andreas
13 Jun 2020 hep-th arxiv.org/abs/2006.07557

We present a nonabelian Lagrangian that appears to have $(2,0)$ superconformal symmetry and that can be coupled to a supergravity background. But for our construction to work, we have to break this superconformal symmetry by imposing as a constraint on top of the Lagrangian that the fields have vanishing Lie derivatives along a Killing direction.

Renormalization of the Einstein-Hilbert action

Gustavsson Andreas
11 Nov 2019 hep-th gr-qc arxiv.org/abs/1911.04178

We examine how the Einstein-Hilbert action is renormalized by adding the usual counterterms and additional corner counterterms when the boundary surface has corners. A bulk geometry asymptotic to $H^{d+1}$ can have boundaries $S^k \times H^{d-k}$ and corners for $0\leq k<d$. We show that the conformal anomaly when $d$ is even is independent of $k$. When $d$ is odd the renormalized action is a finite term that we show is independent of $k$ when $k$ is also odd. When $k$ is even we were unable to extract the finite term using the counterterm method and we address this problem using instead the Kounterterm method. We also compute the mass of a two-charged black hole in AdS$_7$ and show that background subtraction agrees with counterterm renormalization only if we use the infinite series expansion for the counterterm.

Nonabelian M5-brane on $S^6_q$

Bak Dongsu, Gustavsson Andreas
17 Jun 2019 hep-th arxiv.org/abs/1906.07344

We compute the conformal anomaly of a nonabelian M5 brane on $S^1_q\times H^5$ in the large $N$ limit by using the gravity dual of a black hole. We also obtain a general formula for this conformal anomaly for any gauge group by combining various results already present in the literature. From the conformal anomaly we extract the Casimir energy on $\mathbb{R} \times S^5$. We find agreement with the proposal in arXiv:1507.08553.

Abelian M5-brane on $S^6_q$

Gustavsson Andreas
16 Apr 2019 hep-th arxiv.org/abs/1904.07799

We compute the conformal anomaly of the abelian M5 brane on a conical deformation $S^6_q$ of the round six-sphere. Our results agree with corresponding results on $S^1 \times \mathbb{H}^5$ that were obtained in arXiv:1511.00313. For the free energies we obtain missing Casimir energy contributions, inconsequental for the Renyi entropies, and we obtain the proposed constant shift for the Renyi entropy of the selfdual two-form.

Abelian M5-brane on $S^6$

Gustavsson Andreas
11 Feb 2019 hep-th arxiv.org/abs/1902.04201

We study the abelian M5 brane on $S^6$. From the spectrum we extract a series expansion for the heat kernel. In particular we determine the normalization for the coefficient $a$ in the M5 brane conformal anomaly. When we compare our result with what one gets by computing the Hadamard-Minakshisundaram-DeWitt-Seeley coefficients from local curvature invariants on $S^6$, we first find a mismatch of one unit. This mismatch is due to an overcounting of one zero mode. After subtracting this contribution, we finally find agreement. We perform dimensional reduction along a singular circle fiber to five dimensions where we find the conformal anomaly vanishes.

Five-dimensional Super-Yang-Mills and its Kaluza-Klein tower

Gustavsson Andreas
05 Dec 2018 hep-th arxiv.org/abs/1812.01897

We compactify the abelian 6d (1,0) tensor multiplet on a circle bundle, thus reducing the theory down to 5d SYM while keeping all the KK modes. This abelian classical field theory, when interpreted suitably, has a nonlocal superconformal symmetry. Furthermore, a nonabelian generalization, where all the KK modes are kept, is possible for the nonlocal superconformal symmetry, whereas for the local superconformal symmetry we can only realize a subgroup.

A proposal for the non-Abelian tensor multiplet

Gustavsson Andreas
03 Oct 2018 hep-th arxiv.org/abs/1810.01701

If one compactifies the Abelian $(1,0)$ tensor multiplet on a circle, one finds 5d SYM for the zero modes. For the Kaluza-Klein modes one can likewise find a Lagrangian description in 5d \cite{Bonetti:2012st}. Since in 5d we have an ordinary YM gauge potential, one may look for a non-Abelian generalization and indeed such a non-Abelian generalization was found in \cite{Bonetti:2012st}. In this paper, we study this non-Abelian generalization for the $(1,0)$ tensor multiplet in detail. We obtain the supersymmetry variations that we close on-shell. This way we get the fermionic equation of motion and a modified selfduality constraint.

The non-Abelian tensor multiplet

Gustavsson Andreas
11 Apr 2018 hep-th arxiv.org/abs/1804.04035

We assume the existence of a background vector field that enables us to make an ansatz for the superconformal transformations for the non-Abelian 6d $(1,0)$ tensor multiplet. Closure of supersymmetry on generators of the conformal algebra, requires that the vector field is Abelian, has scaling dimension minus one and that the supersymmetry parameter as well as all the fields in the tensor multiplet have vanishing Lie derivatives along this vector field. We couple the tensor multiplet to a hypermultiplet and obtain superconformal transformations that we close off-shell.

Superconformal indices on $S^1\times (S^5/Z_p)$

Gustavsson Andreas
23 Jan 2018 hep-th arxiv.org/abs/1801.07531

We obtain generating functions associated to the abelian superconformal indices for 6d $(1,0)$ tensor and hypermultiplets on $S^1\times (S^5/Z_p)$. We extract the superconformal indices and their high and low temperature behaviors. We consider round and generically squashed $S^5$ in turn. We show that the unsquashed limit of the superconformal indices is smooth. We examine S-duality in the large $p$ limit that acts by exchanging the Hopf circle with the temporal circle.

Five-dimensional fermionic Chern-Simons theory

Bak Dongsu, Gustavsson Andreas
08 Oct 2017 hep-th arxiv.org/abs/1710.02841

We study 5d fermionic CS theory with a fermionic 2-form gauge potential. This theory can be obtained from 5d MSYM theory by performing the maximal topological twist. We put the theory on a five-manifold and compute the partition function. We find that it is a topological quantity, which involves the Ray-Singer torsion of the five-manifold. For abelian gauge group we consider the uplift to the 6d theory and find a mismatch between the 5d partition function and the 6d index, due to the nontrivial dimensional reduction of a selfdual two-form gauge field on a circle. We also discuss an application of the 5d theory to generalized knots made of 2d sheets embedded in 5d.