Jack-Laurent symmetric functions for special values of parameters

Jack-Laurent symmetric functions for special values of parameter

Generalized Calogero-Moser systems from rational Cherednik algebras

We consider ideals of polynomials vanishing on the W-orbits of the intersections of mirrors of a finite reflection group W. We determine all such ideals which are invariant under the action of the corresponding rational Cherednik algebra hence form submodules in the polynomial module. We show that a quantum integrable system can be defined for every such ideal for a real reflection group W. This leads to known and new integrable systems of Calogero-Moser type which we explicitly specify. In the case of classical Coxeter groups we also obtain generalized Calogero-Moser systems with added quadratic potential.Comment: 36 pages; the main change is an improvement of section 7 so that it now deals with an arbitrary complex reflection group; Selecta Math, 201

Coxeter discriminants and logarithmic Frobenius structures

We consider a class of solutions of the WDVV equation related to the special systems of covectors (called $\vee$-systems) and show that the corresponding logarithmic Frobenius structures can be naturally restricted to any intersection of the corresponding hyperplanes. For the Coxeter arrangements the corresponding structures are shown to be almost dual in Dubrovin's sense to the Frobenius structures on the strata in the discriminants discussed by Strachan. For the classical Coxeter systems this leads to the families of $\vee$-systems from the earlier work by Chalykh and Veselov. For the exceptional Coxeter systems we give the complete list of the corresponding $\vee$-systems. We present also some new families of $\vee$-systems, which can not be obtained in such a way from the Coxeter systems.Comment: 28 pages, minor corrections mad

JINR-IAP FEM oscillator with Bragg resonator

A FEM-oscillator with a reversed guide magnetic field and a Bragg resonator as a RF radiation source for collider applications was studied. The configuration with a step of the corrugation phase is proved to be advantageous. It possesses such features as a high efficiency, precise tunability of the operating frequency and a narrow spectral band. It is demonstrated experimentally that such an oscillator is capable of operating at frequencies of ~30 GHz in single-mode regime with the frequency tuning in interval up to 6%. Frequency and spectrum measurements have been performed with precision of ~0.1%

JINR activity in microwave sources for TeV range linear colliders

Results of theoretical and experimental studies of the microwave radiation sources on the base of the induction linac LIU-3000 (JINR, Dubna) are presented. In particular, a FEM-oscillator with the reversed guide magnetic field and Bragg resonator as well as an electron beam buncher in the two-beam accelerator (TBA) driver was studied

A Unified Algebraic Approach to Few and Many-Body Correlated Systems

The present article is an extended version of the paper {\it Phys. Rev.} {\bf B 59}, R2490 (1999), where, we have established the equivalence of the Calogero-Sutherland model to decoupled oscillators. Here, we first employ the same approach for finding the eigenstates of a large class of Hamiltonians, dealing with correlated systems. A number of few and many-body interacting models are studied and the relationship between their respective Hilbert spaces, with that of oscillators, is found. This connection is then used to obtain the spectrum generating algebras for these systems and make an algebraic statement about correlated systems. The procedure to generate new solvable interacting models is outlined. We then point out the inadequacies of the present technique and make use of a novel method for solving linear differential equations to diagonalize the Sutherland model and establish a precise connection between this correlated system's wave functions, with those of the free particles on a circle. In the process, we obtain a new expression for the Jack polynomials. In two dimensions, we analyze the Hamiltonian having Laughlin wave function as the ground-state and point out the natural emergence of the underlying linear $W_{1+\infty}$ symmetry in this approach.Comment: 18 pages, Revtex format, To appear in Physical Review

Free electron lasers based on LINAC-800

The project “FELs and LINAC-800” is being under development at JINR. It is based on an accelerator facility presented to JINR by NIKHEF, Amsterdam. Analysis has shown that it is possible to build in Dubna a universal light source with unique characteristics consisting of a complex of Free Electron Lasers (FEL) covering continuously the wavelength range from far-infrared (150 µm) down to ultraviolet (150 nm). Besides, LINAC-800 could be used for different applications and as an injector for the next generation synchrotron radiation source.Проект ЛСЭ и ЛИНАК-800 реализуется в ОИЯИ. Он основан на ускорительном оборудовании, предоставленном ОИЯИ NIKHEF (Амстердам). Анализ показывает, что в Дубне станет возможным сооружение универсального источника с уникальными характеристиками, состоящего из комплекса лазеров на свободных электронах (ЛСЭ), покрывающих непрерывно длины волн от дальнего инфракрасного излучения (150 мкм) до ультрафиолета (150 нм).Проект ЛСЕ і ЛІНАК-800 реалізується в ОІЯД. Він заснований на прискорювальному устаткуванні, що було дано ОІЯД NІKHEF (Амстердам). Аналіз показує, що в Дубні стане можливим спорудження універсального джерела з унікальними характеристиками, що складається з комплексу лазерів на вільних електронах (ЛВЕ), що перекривають безперервно довжини хвиль від далекого інфрачервоного випромінювання (150 мкм) до ультрафіолету (150 нм)

The Scientific Foundations of Forecasting Magnetospheric Space Weather

The magnetosphere is the lens through which solar space weather phenomena are focused and directed towards the Earth. In particular, the non-linear interaction of the solar wind with the Earth's magnetic field leads to the formation of highly inhomogenous electrical currents in the ionosphere which can ultimately result in damage to and problems with the operation of power distribution networks. Since electric power is the fundamental cornerstone of modern life, the interruption of power is the primary pathway by which space weather has impact on human activity and technology. Consequently, in the context of space weather, it is the ability to predict geomagnetic activity that is of key importance. This is usually stated in terms of geomagnetic storms, but we argue that in fact it is the substorm phenomenon which contains the crucial physics, and therefore prediction of substorm occurrence, severity and duration, either within the context of a longer-lasting geomagnetic storm, but potentially also as an isolated event, is of critical importance. Here we review the physics of the magnetosphere in the frame of space weather forecasting, focusing on recent results, current understanding, and an assessment of probable future developments.Peer reviewe

Energetic particle influence on the Earth's atmosphere

This manuscript gives an up-to-date and comprehensive overview of the effects of energetic particle precipitation (EPP) onto the whole atmosphere, from the lower thermosphere/mesosphere through the stratosphere and troposphere, to the surface. The paper summarizes the different sources and energies of particles, principally galactic cosmic rays (GCRs), solar energetic particles (SEPs) and energetic electron precipitation (EEP). All the proposed mechanisms by which EPP can affect the atmosphere are discussed, including chemical changes in the upper atmosphere and lower thermosphere, chemistry-dynamics feedbacks, the global electric circuit and cloud formation. The role of energetic particles in Earth’s atmosphere is a multi-disciplinary problem that requires expertise from a range of scientific backgrounds. To assist with this synergy, summary tables are provided, which are intended to evaluate the level of current knowledge of the effects of energetic particles on processes in the entire atmosphere

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society