8 research outputs found
Seminal magnetic fields from Inflato-electromagnetic Inflation
We extend some previous attempts to explain the origin and evolution of
primordial magnetic fields during inflation induced from a 5D vacuum. We show
that the usual quantum fluctuations of a generalized 5D electromagnetic field
cannot provide us with the desired magnetic seeds. We show that special fields
without propagation on the extra non-compact dimension are needed to arrive to
appreciable magnetic strengths. We also identify a new magnetic tensor field
in this kind of extra dimensional theories. Our results are in very
good agreement with observational requirements, in particular from TeV Blazars
and CMB radiation limits we obtain that primordial cosmological magnetic fields
should be close scale invariance.Comment: Improved version. arXiv admin note: text overlap with arXiv:1007.3891
by other author
Large-scale magnetic fields from inflation due to a -even Chern-Simons-like term with Kalb-Ramond and scalar fields
We investigate the generation of large-scale magnetic fields due to the
breaking of the conformal invariance in the electromagnetic field through the
-even dimension-six Chern-Simons-like effective interaction with a fermion
current by taking account of the dynamical Kalb-Ramond and scalar fields in
inflationary cosmology. It is explicitly demonstrated that the magnetic fields
on 1Mpc scale with the field strength of G at the present time
can be induced.Comment: 18 pages, 6 figures, version accepted for publication in Eur. Phys.
J.
Non-minimal Maxwell-Modified Gauss-Bonnet Cosmologies: Inflation and Dark Energy
In this paper we show that power-law inflation can be realized in non-minimal
gravitational coupling of electromagnetic field with a general function of
Gauss-Bonnet invariant. Such a non-minimal coupling may appear due to quantum
corrections. We also consider modified Maxwell- gravity in which
non-minimal coupling between electromagnetic field and occur in the
framework of modified Gauss-Bonnet gravity. It is shown that inflationary
cosmology and late-time accelerated expansion of the universe are possible in
such a theory.Comment: 10 pages, no figur
Long term outcome of acute pancreatitis in Italy: Results of a multicentre study
Background: In Italy, no long-term studies regarding the natural history of acute pancreatitis have been carried out. Aim: To report the results of a follow-up on a large series of patients hospitalised for pancreatitis. Methods: Data of 631 patients admitted to 35 Italian hospitals were retrospectively evaluated 51.7 ± 8.4 months after discharge. Results: The average recovery time after mild or severe pancreatitis was 28.2 and 53.4 days respectively. Fourteen sequelae were not resolved and 9 cases required late surgical intervention. Eighty patients (12.7%) had a second hospital admission. Of the patients with mild biliary pancreatitis, 67.9% underwent a cholecystectomy. The overall incidence of relapse was 12.7%. Mortality was 9.8% and no death was related to pancreatitis. Three patients died from carcinoma of the pancreas. Conclusion: Reported recovery time after an attack of pancreatitis was longer than expected in the mild forms. The treatment of sequelae was delayed beyond one year after discharge. The incidence of relapse of biliary pancreatitis in patients not undergoing a cholecystectomy was low, due to endoscopic treatment. Mortality from pancreatic-related causes is low, but there is an association with malignant pancreatic or ampullary tumours not diagnosed during the acute phase of the illness
Long term outcome of acute pancreatitis in Italy: Results of a multicentre study
Background: In Italy, no long-term studies regarding the natural history of acute pancreatitis have been carried out. Aim: To report the results of a follow-up on a large series of patients hospitalised for pancreatitis. Methods: Data of 631 patients admitted to 35 Italian hospitals were retrospectively evaluated 51.7 \ub1 8.4 months after discharge. Results: The average recovery time after mild or severe pancreatitis was 28.2 and 53.4 days respectively. Fourteen sequelae were not resolved and 9 cases required late surgical intervention. Eighty patients (12.7%) had a second hospital admission. Of the patients with mild biliary pancreatitis, 67.9% underwent a cholecystectomy. The overall incidence of relapse was 12.7%. Mortality was 9.8% and no death was related to pancreatitis. Three patients died from carcinoma of the pancreas. Conclusion: Reported recovery time after an attack of pancreatitis was longer than expected in the mild forms. The treatment of sequelae was delayed beyond one year after discharge. The incidence of relapse of biliary pancreatitis in patients not undergoing a cholecystectomy was low, due to endoscopic treatment. Mortality from pancreatic-related causes is low, but there is an association with malignant pancreatic or ampullary tumours not diagnosed during the acute phase of the illness. \ua9 2013 Editrice Gastroenterologica Italiana S.r.l
Runaway electron beam control
Post-disruption runaway electron (RE) beams in tokamaks with large current can cause deep melting of the vessel and are one of the major concerns for ITER operations. Consequently, a considerable effort is provided by the scientific community in order to test RE mitigation strategies. We present an overview of the results obtained at FTU and TCV controlling the current and position of RE beams to improve safety and repeatability of mitigation studies such as massive gas (MGI) and shattered pellet injections (SPI). We show that the proposed RE beam controller (REB-C) implemented at FTU and TCV is effective and that current reduction of the beam can be performed via the central solenoid reducing the energy of REs, providing an alternative/parallel mitigation strategy to MGI/SPI. Experimental results show that, meanwhile deuterium pellets injected on a fully formed RE beam are ablated but do not improve RE energy dissipation rate, heavy metals injected by a laser blow off system on low-density flat-top discharges with a high level of RE seeding seem to induce disruptions expelling REs. Instabilities during the RE beam plateau phase have shown to enhance losses of REs, expelled from the beam core. Then, with the aim of triggering instabilities to increase RE losses, an oscillating loop voltage has been tested on RE beam plateau phase at TCV revealing, for the first time, what seems to be a full conversion from runaway to ohmic current. We finally report progresses in the design of control strategies at JET in view of the incoming SPI mitigation experiments