D=4, N=2 Supergravity with Abelian electric and magnetic charges

We discuss the relation between standard N=2 supergravity with translational gauging and N=2 supergravities with scalar-tensor multiplets with massive tensors and Abelian electric charges. We point out that a symplectic covariant formulation of N=2 supergravity can be achieved just in the presence of tensor multiplets. As a consequence one can see that the formulation of the N=2 theory as it comes from IIB flux compactification, which is included in these models, is equivalent to a non perturbative phase of standard N=2 supergravity. It is also shown that the IIB tadpole cancellation condition is imposed by supersymmetry in four dimensions.Comment: 10 pages LaTex, no figure

D=4, N=2 Supergravity in the Presence of Vector-Tensor Multiplets and the Role of higher p-forms in the Framework of Free Differential Algebras

We thoroughly analyze at the bosonic level, in the framework of Free Differential Algebras (FDA), the role of 2-form potentials setting in particular evidence the precise geometric formulation of the anti-Higgs mechanism giving mass to the tensors. We then construct the (super)-FDA encoding the coupling of vector-tensor multiplets in D=4, N=2 supergravity, by solving the Bianchi identities in superspace and thus retrieving the full theory up to 3-fermions terms in the supersymmetry transformation laws, leaving the explicit construction of the Lagrangian to future work. We further explore the extension of the bosonic FDA in the presence of higher p-form potentials, focussing our attention to the particular case p=3, which would occur in the construction of D=5, N=2 supergravity where some of the scalars are properly dualized.Comment: 39 pages, improved introduction, section 4 and Appendices modified, typos corrected, citations adde

Poincare' dual of D=4 N=2 Supergravity with Tensor Multiplets

We study, in an arbitrary even number D of dimensions, the duality between massive D/2 tensors coupled to vectors, with masses given by an arbitrary number of ``electric'' and ``magnetic'' charges, and (D/2-1) massive tensors. We develop a formalism to dualize the Lagrangian of D=4, N=2 supergravity coupled to tensor and vector multiplets, and show that, after the dualization, it is equivalent to a standard D=4, N=2 gauged supergravity in which the Special Geometry quantities have been acted on by a suitable symplectic rotation.Comment: 15 pages, JHEP3 class, v2 typos corrected, references adde

D=4, N=2 Gauged Supergravity coupled to Vector-Tensor Multiplets

We construct the general four-dimensional N=2 supergravity theory coupled to vector and vector-tensor multiplets only. Consistency of the construction requires the introduction of the vector fields dual to those sitting in the same supermultiplets as the antisymmetric tensors, as well as the scalar fields dual to the tensors themselves. Gauge symmetries also involving these additional fields guarantee the correct counting of the physical degrees of freedom.Comment: Typos corrected, references adde

Triality Invariance in the N=2 Superstring

We prove the discrete triality invariance of the N=2 NSR superstring moving in a D=2+2 target space. We find that triality holds also in the Siegel-Berkovits formulation of the selfdual superstring. A supersymmetric generalization of Cayley's hyperdeterminant, based on a quartic invariant of the SL(2|1)^3 superalgebra, is presented.Comment: 11 pages, 1 figure, LaTeX. Misprints corrected in the supermatrices of eq. (5.2

Theory of Superdualities and the Orthosymplectic Supergroup

We study the dualities for sigma models with fermions and bosons. We found that the generalization of the SO(m,m) duality for D=2 sigma models and the Sp(2n) duality for D=4 sigma models is the orthosymplectic duality OSp(m,m|2 n). We study the implications of this and we derive the most general D=2 sigma model, coupled to fermionic and bosonic one-forms, with such dualities. To achieve this we generalize Gaillard-Zumino analysis to orthosymplectic dualities, which requires to define embedding of the superisometry group of the target space into the duality group. We finally discuss the recently proposed fermionic dualities as a by-product of our construction.Comment: 35 pages, LaTeX sourc

Cold dust and low [O iii]/[C ii] ratios: an evolved star-forming population at redshift 7

We present new ALMA Band 8 (rest-frame 90 μm) continuum observations of three massive (M⋆ ≈ 1010 M⊙) galaxies at z ≈ 7 previously detected in [C II]158 μm and underlying dust continuum emission in the Reionization Era Bright Emission Line Survey (REBELS). We detect dust emission from two of our targets in Band 8 (REBELS-25 and REBELS-38), while REBELS-12 remains undetected. Through optically thin modified blackbody fitting, we determine dust temperatures of Tdust ≈ 30 − 35 K in both of the dual-band detected targets, indicating they are colder than most known galaxies at z ∼ 7. Moreover, their inferred dust masses are large (Mdust ≈ 108 M⊙), albeit still consistent with models of high-redshift dust production. We furthermore target and detect [O III]88 μm emission in both REBELS-12 and REBELS-25, and find L[O III]/L[C II] ≈ 1 − 1.5 – low compared to the L[O III]/L[C II] ≳ 2 − 10 observed in the known z ≳ 6 population thus far. We argue the lower line ratios are due to a comparatively weaker ionizing radiation field resulting from the less starbursty nature of our targets, although the possibility of REBELS-12 being a merger of an [O III]-bright and [O III]-faint component prevents the unambiguous interpretation of its [O III]/[C II] ratio. Nevertheless, a low burstiness forms a natural explanation for the cold dust temperatures and low [O III]λλ4959, 5007 + Hβ equivalent widths of REBELS-25 and REBELS-38. Overall, these observations provide evidence for the existence of a massive, dust-rich galaxy population at z ≈ 7 which has previously experienced vigorous star formation, but is currently forming stars in a steady, as opposed to bursty, manner