Magnetic quivers from brane webs with O7+-planes

We consider the Higgs branch of 5d fixed points engineered using brane webs with an O7+-plane. We use the brane construction to propose a set of rules to extract the corresponding magnetic quivers. Such magnetic quivers are generically framed non-simply-laced quivers containing unitary as well as special unitary gauge nodes. We compute the Coulomb branch Hilbert series of the proposed magnetic quivers. In some specific cases, an alternative magnetic quiver can be obtained either using an ordinary brane web or a brane web with an O5-plane. In these cases, we find a match at the level of the Hilbert series

Dualitites in quantum field theory from string theory

Quantum field theory (QFT), is a powerful framework to study diverse phenomena in physics. The range of topics includes the interactions of elementary particles, the continuum limit of condensed matter systems defined on a lattice, models of the expanding universe, as well as quantum gravity. Despite its enormous breadth of applications, it is still quite poorly understood. From a pragmatic point of view, a generic QFT is well understood in the per-turbative regime, where one has a small expansion parameter or coupling constant. That we have a satisfactory understanding of QFTs in the weakly coupled regime, is highlighted by the fact that we have a single formalism, namely feynman diagrams, that can be applied to any weakly coupled theory. Conversely, there is no universal framework to understand non-perturbative and strong coupling phenomena. Instead, we have a distinct set of tools, which apply to distinct sets of very special theories, such as those with supersymmetry or topolog-ical theories. From this perspective, to understand the strong coupling dynamics of a QFT, is to develop a unique formalism that can be applied to solve a generic strongly coupled QFT. The reader should be warned that this thesis will not achieve such an ambitious goal. How-ever, it is good to keep this general philosophy in mind, as a broader motivation for some of the work presented. We will provide, instead, a collection of data points for particular sec-tors of strongly coupled QFTs that are under analytic control. One can hope that some day, these data points can provide the foundations for a more systematic and universal approach. From a more formal viewpoint, quantum field theory, as of yet, has no rigorous mathemati-cal basis. This is particularly bothersome, given the deep interconnections between ideas in modern mathematics and those of QFT [1]. The goal of this thesis is to introduce its reader to a few notable examples, where the former issue can be overcome. The unifying theme of all these examples is their relation to brane dynamics in string theory [2]. We will make extensive use of the string theory embedding of the QFTs under consideration, in order to illuminate their strong coupling dynamics

Electrostatic description of 3d N \mathcal{N} = 4 linear quivers

We present the holographic dual for the strongly coupled, low energy dynamics of balanced N = 4 field theories in (2 + 1) dimensions. The infinite family of Type IIB backgrounds with AdS4 × S2 × S2 factors is described in terms of a Laplace problem with suitable boundary conditions. The system describes an array of D3, NS5 and D5 branes. We study various aspects of these Hanany-Witten set-ups (number of branes, linking numbers, dimension of the Higgs and Coulomb branches) and encode them in holographic calculations. A generic expression for the Free Energy/Holographic Central Charge is derived. These quantities are then calculated explicitly in various general examples. We also discuss how Mirror Symmetry is encoded in our Type IIB backgrounds. The connection with previous results in the bibliography is made

5d SCFTs and their non-supersymmetric cousins

We consider generalisations of the recently proposed supersymmetry breaking deformation of the 5d rank-1 $E_1$ superconformal field theory to higher rank. We generalise the arguments to theories which admit a mass deformation leading to gauge theories coupled to matter hypermultiplets at low energies. These theories have a richer space of non-supersymmetric deformations, due to the existence of a larger global symmetry. We show that there is a one-to-one correspondence between the non-SUSY deformations of the gauge theory and their $(p,q)$ 5-brane web. We comment on the (in)stability of these deformations both from the gauge theory and the 5-brane web point of view. UV duality plays a key role in our analysis, fixing the effective Chern-Simons level for the background vector multiplets, together with their complete prepotential. We partially classify super-Yang-Mills theories known to enjoy UV dualities which show a phase transition where different phases are separated by a jump of Chern-Simons levels of both a perturbative and an instantonic global symmetry. When this transition can be reached by turning on a non-supersymmetric deformation of the UV superconformal field theory, it can be a good candidate to host a 5d non-supersymmetric CFT. We also discuss consistency of the proposed phase diagram with the 't Hooft anomalies of the models that we analyse.Comment: references added, minor typos correcte

Matrix Models and Holography: Mass Deformations of Long Quiver Theories in 5d and 3d

We enlarge the dictionary between matrix models for long linear quivers preserving eight supercharges in $d=5$ and $d=3$ and type IIB supergravity backgrounds with AdS$_{d+1}$ factors. We introduce mass deformations of the field theory that break the quiver into a collection of interacting linear quivers, which are decoupled at the end of the RG flow. We find and solve a Laplace problem in supergravity which realises these deformations holographically. The free energy and expectation values of antisymmetric Wilson loops are calculated on both sides of the proposed duality, finding agreement. Our matching procedure sheds light on the F-theorem in five dimensions.Comment: 46 pages plus appendices. Various figures. Some improvements and references added. SciPost Physics versio

Phases of U (Nc) QCD3 from type 0 strings and Seiberg duality

We propose an embedding of U(Nc) QCD3 with a Chern-Simons term in string theory and Seiberg duality

Five-brane webs, Higgs branches and unitary/orthosymplectic magnetic quivers

We study the Higgs branch of 5d superconformal theories engineered from brane webs with orientifold five-planes. We propose a generalization of the rules to derive magnetic quivers from brane webs pioneered in arXiv:2004.04082, by analyzing theories that can be described with a brane web with and without O5 planes. Our proposed magnetic quivers include novel features, such as hypermultiplets transforming in the fundamental-fundamental representation of two gauge nodes, antisymmetric matter, and $\mathbb{Z}_2$ gauge nodes. We test our results by computing the Coulomb and Higgs branch Hilbert series of the magnetic quivers obtained from the two distinct constructions and find agreement in all cases.Comment: 67 pages, 57 figures, 24 tables, 4 appendices, minor corrections, matches with the published versio

Approach evaluation of the role of Dry lands development in water management optimization and planning

The growing population and, consequently, the need to produce crops on the one hand and the limitation of water resources as an important factor in agricultural production have led to the intensification of the problem of dehydration in many parts of the world, including Iran. Therefore, a balance between water resource constraints and agricultural development is essential. In this regard, the International Water Management Organization (IMO) has estimated in its comprehensive assessment that water management in agriculture in rainforests could lead to a 75% increase in global food products (Di Dono, 2009). Therefore, agricultural development through the development of dry land areas can be considered as a logical solution in the context of the water crisis (Akhavan et al. 2013)

The Hitchhiker's Guide to 4d N=2\mathcal{N}=2 Superconformal Field Theories

Superconformal field theory with $\mathcal{N}=2$ supersymmetry in four dimensional spacetime provides a prime playground to study strongly coupled phenomena in quantum field theory. Its rigid structure ensures valuable analytic control over non-perturbative effects, yet the theory is still flexible enough to incorporate a large landscape of quantum systems. Here we aim to offer a guidebook to fundamental features of the 4d $\mathcal{N}=2$ superconformal field theories and basic tools to construct them in string/M-/F-theory. The content is based on a series of lectures at the Quantum Field Theories and Geometry School (https://sites.google.com/view/qftandgeometrysummerschool/home) in July 2020.Comment: v3: Improved discussion, fixed typos, added references v2: Typos fixed and added references. v1: 96 pages. Based on a series of lectures at the Quantum Field Theories and Geometry School in July 202

The effect of electrical low-frequency stimulation on balance and locomotor activity in adult male rats during epileptogenesis of dorsal hippocampal

Background: Epilepsy is the third world neurological disorder. Epileptic focus causes motor impairment by sending projections to different areas of the brain such as areas which are related to movement control. Regarding the inhibitory effect of low-frequency electrical stimulation (LFS) on seizure wave's transmission, this study aimed at examining the effect of LFS during the epileptogenesis of dorsal hippocampal on balance and locomotor activity in adult male rats using the kindling method. Materials and Methods: Fifty rats were randomly divided into 5 groups: Control, Sham, Kindled, LFS and KLFS. Animals in the kindled group were stimulated rapidly by daily stimulation of dorsal hippocampus (1 ms pulse duration at 50Hz for 3 seconds). Animals in the sham and control groups did not receive any stimulation. In the LFS groups, four LFS packages at a frequency of 1 Hz were applied daily. At the end of stimulation, motor activity and balance were assessed by open-field and rotarod tests. Results: Frequency of rearing and grooming in the Kindled group significantly increased compared to the control group (P<0.05). Balance in the Kindled group was significantly decreased (P<0.05). LFS induction during hippocampal kindling did not show any significant difference in any of the mentioned parameters with the control group. Conclusion: In summary, applying low-frequency electrical stimulation during hippocampal kindling can reduce the motor activity and improve balance