Multimetric Supergravities

Making use of integral forms and superfield techniques we propose supersymmetric extensions of the multimetric gravity Lagrangians in dimensions one, two, three and four. The supersymmetric interaction potential covariantly deforms the bosonic one, producing in particular suitable super-symmetric polynomials generated by the Berezinian. As an additional application of our formalism we construct supersymmetric multi-Maxwell theories in dimensions three and four.Comment: 37 pages, Latex2e, no figure

Low frequency geomagnetic field fluctuations at low latitude during the passage of a higher pressure solar wind region

International audienceThe passage of a higher pressure solar wind region at the Earth's orbit marked the onset of low latitude (L=1.6) fluctuations in the frequency range (0.8?5.5 mHz) for both the horizontal geomagnetic field components. Spectral peaks mostly occur at the same frequencies as the spectral enhancements which appeared in the long term analysis of experimental measurements from the same station and were tentatively interpreted in terms of ground signatures of global magnetospheric modes. A comparison with simultaneous observations discussed by previous investigations allows us to conclude that the same set of frequencies is enhanced in a wide portion of the Earth's magnetosphere

Towards an In-depth Understanding of Deep Packet Inspection Using a Suite of Industrial Control Systems Protocol Packets

Industrial control systems (ICS) are increasingly at risk and vulnerable to internal and external threats. These systems are integral part of our nation’s critical infrastructures. Consequently, a successful cyberattack on one of these could present disastrous consequences to human life and property as well. It is imperative that cybersecurity professionals gain a good understanding of these systems particularly in the area of communication protocols. Traditional Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are made to encapsulate some of these ICS protocols which may enable malicious payload to get through the network firewall and thus, gain entry into the network. This paper describes technical details on various ICS protocols and a suite of ICS protocol packets for the purpose of providing digital forensic materials for laboratory exercises toward a better understanding of the inner workings of ICS communications. Further, these artifacts can be useful in devising deep packet inspection (DPI) strategies that can be implemented in network firewalls, in expanding challenge materials for cyber competitions, and in attribution, vulnerability assessment, and penetration testing research in ICS security. We also present software tools that are available for free download on the Internet that could be used to generate simulated ICS and Supervisory Control and Data Acquisition (SCADA) communication packets for research and pedagogical purposes. Finally, we conclude the paper by presenting possible research avenues that can be pursued as extensions to this seminal work on ICS security. Prominent among these possible extensions is the expansion of the ICS packet suite to include those protocols in the wireless domain such as Wi-Fi (802.11), Bluetooth, Zigbee, and other protocols that utilizes proprietary Radio Frequency

Massless fermions in a bag at finite density and temperature

We introduce the chemical potential in a system of massless fermions in a bag by impossing boundary conditions in the Euclidean time direction. We express the fermionic mean number in terms of a functional trace involving the Green's function of the boundary value problem, which we study analytically. Numerical evaluations are made, and an application to a simple hadron model is discussed.Comment: 14 pages, 3 figures, RevTe

On the relation between local and geometric Lagrangians for higher spins

Equations of motion for free higher-spin gauge fields of any symmetry can be formulated in terms of linearised curvatures. On the other hand, gauge invariance alone does not fix the form of the corresponding actions which, in addition, either contain higher derivatives or involve inverse powers of the d'Alembertian operator, thus introducing possible subtleties in degrees of freedom count. We suggest a path to avoid ambiguities, starting from local, unconstrained Lagrangians previously proposed, and integrating out the auxiliary fields from the functional integral, thus generating a unique non-local theory expressed in terms of curvatures.Comment: 14 pages. Contribution to the proceedings of the 1st Mediterranean Conference on Classical and Quantum Gravity, Kolymbary (Crete, Greece) September 14-18 200

Confined two-dimensional fermions at finite density

We introduce the chemical potential in a system of two-dimensional massless fermions, confined to a finite region, by imposing twisted boundary conditions in the Euclidean time direction. We explore in this simple model the application of functional techniques which could be used in more complicated situations.Comment: 15 pages, LaTe

Finite density and temperature in hybrid bag models

We introduce the chemical potential in a system of two-flavored massless fermions in a chiral bag by imposing boundary conditions in the Euclidean time direction. We express the fermionic mean number in terms of a functional trace involving the Green function of the boundary value problem, which is studied analytically. Numerical evaluations for the fermionic number are presented.Comment: 19 pages, 4 figure

Pc5 geomagnetic field fluctuations at discrete frequencies at a low latitude station

International audienceA statistical analysis of the geomagnetic field fluctuations in the Pc5 frequency range (1?5 mHz) at a low latitude station (L = 1.6) provides further evidence for daytime power peaks at discrete frequencies. The power enhancements, which become more pronounced during high solar wind pressure conditions, may be interpreted in terms of ground signatures of magnetospheric cavity/waveguide compressional modes driven by solar wind pressure pulses. In this sense, the much clearer statistical evidence for afternoon events can be related to corotating structures mainly impinging the postnoon magnetopause. A comparison with results obtained for the same time intervals from previous investigations at higher latitudes and in the Earth's magnetosphere confirms the global character of the observed modes

Geomagnetic field fluctuations during the passage at the Earth's orbit of the tail of the 15?16 July 2000 ejecta

International audienceIn this work we present the analysis of the geomagnetic field fluctuations observed at different ground stations (approximately along two latitudinal arrays, separated by several hours in local time) during the passage at the Earth's orbit of the tail of the 15?16 July 2000 coronal ejecta. The time interval of interest is characterized by northward interplanetary magnetic field conditions and several changes in the solar wind dynamic pressure. We found at all stations, both in the local morning and in the local evening, simultaneous and highly coherent waves at the same discrete frequencies (~ 1.8 and ~ 3.6 mHz) and suggest a possible interpretation in terms of global compressional modes driven by an impulsive variation of the solar wind pressure. Along the array situated in the morning sector, at the highest latitudes, the higher frequency mode seems to couple with the local field line resonance; on the other hand, along the array situated in the evening sector, the characteristics of the observed fluctuations suggest that the highest latitude station could be located at the footprint of open field lines. Our results also show that solar wind pressure variations observed during the recovery phase of the storm do not find correspondence in the geomagnetic field variations, regardless of local time and latitude; conversely, some hours later continuous solar wind pressure variations find a close correspondence in the geomagnetic field variations at all stations