1,720,984 research outputs found
Entropy function from toric geometry
Full text linkIt has recently been claimed that a Cardy-like limit of the superconformal index of 4d N = 4 SYM accounts for the entropy function, whose Legendre transform corresponds to the entropy of the holographic dual AdS5 rotating black hole. Here we study this Cardy-like limit for N = 1 toric quiver gauge theories, observing that the corresponding entropy function can be interpreted in terms of the toric data. Furthermore, for some families of models, we compute the Legendre transform of the entropy function, comparing with
similar results recently discussed in the literature
The moduli spaces of S-fold CFTs
Full text linkAbstract An S-fold has played an important role in constructing supersymmetric field theories with interesting features. It can be viewed as a type of AdS4 solutions of Type IIB string theory where the fields in overlapping patches are glued by elements of SL(2, ℤ). This paper examines three dimensional quiver theories that arise from brane configurations with an inclusion of the S-fold. An important feature of such a quiver is that it contains a link, which is the T (U(N)) theory, between two U(N) groups, along with bifundamental and fundamental hypermultiplets. We systematically study the moduli spaces of those quiver theories, including the cases in which the non-zero Chern-Simons levels are turned on. A number of such moduli spaces turns out to have a very rich structure and tells us about the brane dynamics in the presence of an S-fold
Variations on S-fold CFTs
Full text linkAbstract A local SL(2, ℤ) transformation on the Type IIB brane configuration gives rise to an interesting class of superconformal field theories, known as the S-fold CFTs. Previously it has been proposed that the corresponding quiver theory has a link involving the T(U(N)) theory. In this paper, we generalise the preceding result by studying quivers that contain a T(G) link, where G is self-dual under S-duality. In particular, the cases of G = SO(2N), USp′(2N) and G 2 are examined in detail. We propose the theories that arise from an appropriate insertion of an S-fold into a brane system, in the presence of an orientifold threeplane or an orientifold fiveplane. By analysing the moduli spaces, we test such a proposal against its S-dual configuration using mirror symmetry. The case of G 2 corresponds to a novel class of quivers, whose brane construction is not available. We present several mirror pairs, containing G 2 gauge groups, that have not been discussed before in the literature
Characterizing the spontaneous collapse of a wavefunction through entropy production
Full text linkObjective-collapse models are a unified dynamics approach to solve the so called “measurement problem” of Quantum Mechanics, namely the conflicting nature of the Schrӧdinger equation and the wave function collapse postulate. Two of the most studied of such models, the Continuous Spontaneous Localization (CSL) models and the Diόsi-Penrose (DP) model, share a similar mathematical structure. While in the CSL model the origin of the noise responsible for the collapse is not discussed, in the DP model this is related to gravity.
In our work, we study the CSL and DP models from a different perspective, investigating the phenomenology leading to the non-conservation of energy predicted by these theories from the viewpoint of non-equilibrium thermodynamics. As a paradigmatic situation currently addressed in frontier experiments aimed at investigating possible collapse theories, we consider a one-dimensional mechanical oscillator in a thermal state. We perform our analysis in the phase space of the oscillator, where the entropy production rate, a non-equilibrium quantity used to characterize irreversibility, can be conveniently analyzed. We show that a thermodynamic consistent dynamics is possible only if the asymptotic state has infinite temperature.
We then repeat the analysis for a dissipative generalization of the models, for which it is possible to characterize the equilibration process in the large temperature limit. In particular, after a preliminary study in the Gaussian limit of the dynamics, we also study the consequences of non-Gaussian effects in the equilibration process
Supersymmetric indices of 3d S-fold SCFTs
Full text linkEnhancement of global symmetry and supersymmetry in the infrared is one of the most intriguing phenomena in quantum field theory. We investigate such phenomena in a large class of three dimensional superconformal field theories, known as the S-fold SCFTs. Supersymmetric indices are computed for a number of theories containing small rank gauge groups. It is found that indices of several models exhibit enhancement of supersymmetry at the superconformal fixed point in the infrared. Dualities between S-fold theories that have different quiver descriptions are also analysed. We explore a new class of theories with a discrete global symmetry, whose gauge symmetry in the quiver has a different global structure from those that have been studied earlier
State estimation with quantum extreme learning machine beyond scrambling time
No full textQuantum extreme learning machines (QELMs) leverage untrained quantum dynamics to efficiently process information encoded in input quantum states, avoiding the high computational cost of training more complicated nonlinear models. On the other hand, quantum information scrambling (QIS) quantifies how the spread of quantum information into correlations makes it irretrievable from local measurements. Here, we explore the tight relation between QIS and the predictive power of QELMs. In particular, we show efficient state estimation is possible even beyond the scrambling time, for many different types of dynamics — in fact, we show that in all the cases we studied, the reconstruction efficiency at long interaction times matches the optimal one offered by random global unitary dynamics. These results offer promising venues for robust experimental QELM-based state estimation protocols, as well as providing novel insights into the nature of QIS from a state estimation perspective
Cubic interactions of Maxwell-like higher spins
Full text linkAbstract We study the cubic vertices for Maxwell-like higher-spins in flat and (A)dS background spaces of any dimension. Reducibility of their free spectra implies that a single cubic vertex involving any three fields subsumes a number of couplings among different particles of various spins. The resulting vertices do not involve traces of the fields and in this sense are simpler than their Fronsdal counterparts. We propose an extension of both the free theory and of its cubic deformation to a more general class of partially reducible systems, that one can obtain from the original theory upon imposing trace constraints of various orders. The key to our results is a version of the Noether procedure allowing to systematically account for the deformations of the transversality conditions to be imposed on the gauge parameters at the free level
Holographic duals of 6d RG flows
Full text linkA notable class of superconformal theories (SCFTs) in six dimensions is parameterized by an integer N , an ADE group G, and two nilpotent elements μ in G. Nilpotent elements have a natural partial ordering, which has been conjectured to coincide with the hierarchy of renormalization-group flows among the SCFTs. In this paper we test this conjecture for G = SU(k), where AdS duals exist in IIA. We work with a seven-dimensional gauged supergravity, consisting of the gravity multiplet and two SU(k) non-Abelian vector multiplets. We show that this theory has many supersymmetric AdS vacua, determined by two nilpotent elements, which are naturally interpreted as IIA AdS solutions. The BPS equations for domain walls connecting two such vacua can be solved analytically, up to a Nahm equation with certain boundary conditions. The latter admit a solution connecting two vacua if and only if the corresponding nilpotent elements are related by the natural partial ordering, in agreement with the field theory conjecture.A notable class of superconformal theories (SCFTs) in six dimensions is parameterized by an integer , an ADE group , and two nilpotent elements in . Nilpotent elements have a natural partial ordering, which has been conjectured to coincide with the hierarchy of renormalization-group flows among the SCFTs. In this paper we test this conjecture for , where AdS duals exist in IIA. We work with a seven-dimensional gauged supergravity, consisting of the gravity multiplet and two non-Abelian vector multiplets. We show that this theory has many supersymmetric AdS vacua, determined by two nilpotent elements, which are naturally interpreted as IIA AdS solutions. The BPS equations for domain walls connecting two such vacua can be solved analytically, up to a Nahm equation with certain boundary conditions. The latter admit a solution connecting two vacua if and only if the corresponding nilpotent elements are related by the natural partial ordering, in agreement with the field theory conjecture
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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