14,864 research outputs found
New nilpotent superfields
We propose new off-shell models for spontaneously broken local
supersymmetry, in which the supergravity multiplet couples to nilpotent
Goldstino superfields that contain either a gauge one-form or a gauge two-form
in addition to spin-1/2 Goldstone fermions and auxiliary fields. In the case of
Poincar\'e supersymmetry, we elaborate on the concept of twisted
chiral superfields and present a nilpotent superfield that
underlies the cubic nilpotency conditions given in arXiv:1707.03414 in terms of
constrained superfields.Comment: 20 pages; V3: typos correcte
Conformally flat supergeometry in five dimensions
Using the superspace formulation for the 5D N = 1 Weyl supermultiplet
developed in arXiv:0802.3953, we elaborate the concept of conformally flat
superspace in five dimensions. For a large family of supersymmetric theories
(including sigma-models and Yang-Mills theories) in the conformally flat
superspace, we describe an explicit procedure to formulate their dynamics in
terms of rigid 4D N = 1 superfields. The case of 5D N = 1 anti-de Sitter
superspace is discussed as an example.Comment: 16 pages, no figures; V2: typos corrected, comments added; V3: typo
in eq. (79) correcte
Field theory in 4D N=2 conformally flat superspace
Building on the superspace formulation for four-dimensional N=2
matter-coupled supergravity developed in arXiv:0805.4683, we elaborate upon a
general setting for field theory in N=2 conformally flat superspaces, and
concentrate specifically on the case of anti-de Sitter (AdS) superspace. We
demonstrate, in particular, that associated with the N=2 AdS supergeometry is a
unique vector multiplet such that the corresponding covariantly chiral field
strength W_0 is constant, W_0=1. This multiplet proves to be intrinsic in the
sense that it encodes all the information about the N=2 AdS supergeometry in a
conformally flat frame. Moreover, it emerges as a building block in the
construction of various supersymmetric actions. Such a vector multiplet, which
can be identified with one of the two compensators of N=2 supergravity, also
naturally occurs for arbitrary conformally flat superspaces. An explicit
superspace reduction N=2 to N=1 is performed for the action principle in
general conformally flat N=2 backgrounds, and examples of such reduction are
given.Comment: 48 pages, LaTex, no figures; V2: typos corrected, eq. (4.50), (4.57)
and (4.63a) modifie
N=4 supersymmetric Yang-Mills theories in AdS_3
For all types of N=4 anti-de Sitter (AdS) supersymmetry in three dimensions,
we construct manifestly supersymmetric actions for Abelian vector multiplets
and explain how to extend the construction to the non-Abelian case. Manifestly
N=4 supersymmetric Yang-Mills (SYM) actions are explicitly given in the cases
of (2,2) and critical (4,0) AdS supersymmetries. The N=4 vector multiplets and
the corresponding actions are then reduced to (2,0) AdS superspace, in which
only N=2 supersymmetry is manifest. Using the off-shell structure of the N=4
vector multiplets, we provide complete N=4 SYM actions in (2,0) AdS superspace
for all types of N=4 AdS supersymmetry. In the case of (4,0) AdS supersymmetry,
which admits a Euclidean counterpart, the resulting N=2 action contains a
Chern-Simons term proportional to q/r, where r is the radius of AdS_3 and q is
the R-charge of a chiral scalar superfield. The R-charge is a linear
inhomogeneous function of X, an expectation value of the N=4 Cotton superfield.
Thus our results explain the mysterious structure of N=4 supersymmetric
Yang-Mills theories on S^3 discovered in arXiv:1401.7952. In the case of (3,1)
AdS supersymmetry, which has no Euclidean counterpart, the SYM action contains
both a Chern-Simons term and a chiral mass-like term. In the case of (2,2) AdS
supersymmetry, which admits a Euclidean counterpart, the SYM action has no
Chern-Simons and chiral mass-like terms.Comment: 45 pages; V3: minor corrections, version published in JHE
Fluctuations in the random-link matching problem
Using the replica approach and the cavity method, we study the fluctuations
of the optimal cost in the random-link matching problem. By means of replica
arguments, we derive the exact expression of its variance. Moreover, we study
the large deviation function, deriving its expression in two different ways,
namely using both the replica method and the cavity method.Comment: 9 pages, 3 figure
Plato's Phaedo: Selected Papers From the Eleventh Symposium Platonicum
The paper deals with the "deuteros plous", literally âthe second voyageâ, proverbially âthe next best wayâ, discussed in Platoâs "Phaedo", the key passage being Phd. 99e4â100a3. The second voyage refers to what Platoâs Socrates calls his âflight into the logoiâ. Elaborating on the subject, the author first (I) provides a non-standard interpretation of the passage in question, and then (II) outlines the philosophical problem that it seems to imply, and, finally, (III) tries to apply this philosophical problem to the "ultimate final proof" of immortality and to draw an analogy with the ontological argument for the existence of God, as proposed by Descartes in his 5th "Meditation". The main points are as follows: (a) the âflight into the logoiâ can have two different interpretations, a common one and an astonishing one, and (b) there is a structural analogy between Descartesâs ontological argument for the existence of God in his 5th "Meditation" and the "ultimate final proof" for the immortality of the soul in the "Phaedo"
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