16,937 research outputs found
Effective action in DSR1 quantum field theory
We present the one-loop effective action of a quantum scalar field with DSR1
space-time symmetry as a sum over field modes. The effective action has real
and imaginary parts and manifest charge conjugation asymmetry, which provides
an alternative theoretical setting to the study of the particle-antiparticle
asymmetry in nature.Comment: 8 page
Rejection Properties of Stochastic-Resonance-Based Detectors of Weak Harmonic Signals
In (V. Galdi et al., Phys. Rev. E57, 6470, 1998) a thorough characterization
in terms of receiver operating characteristics (ROCs) of stochastic-resonance
(SR) detectors of weak harmonic signals of known frequency in additive gaussian
noise was given. It was shown that strobed sign-counting based strategies can
be used to achieve a nice trade-off between performance and cost, by comparison
with non-coherent correlators. Here we discuss the more realistic case where
besides the sought signal (whose frequency is assumed known) further unwanted
spectrally nearby signals with comparable amplitude are present. Rejection
properties are discussed in terms of suitably defined false-alarm and
false-dismissal probabilities for various values of interfering signal(s)
strength and spectral separation.Comment: 4 pages, 5 figures. Misprints corrected. PACS numbers added. RevTeX
Tanaka-Tagoshi Parametrization of post-1PN Spin-Free Gravitational Wave Chirps: Equispaced and Cardinal Interpolated Lattices For First Generation Interferometric Antennas
The spin-free binary-inspiral parameter-space introduced by Tanaka and
Tagoshi to construct a uniformly-spaced lattice of templates at (and possibly
beyond) order is shown to work for all first generation interferometric
gravitational wave antennas. This allows to extend the minimum-redundant
cardinal interpolation techniques of the correlator bank developed by the
Authors to the highest available order PN templates. The total number of 2PN
templates to be computed for a minimal match is reduced by a
factor 4, as in the 1PN case.Comment: 9 pages, 8 figures, 3 tables, accepted for publication in Phys. Rev.
Monitoring thermal ablation via microwave tomography. An ex vivo experimental assessment
Thermal ablation treatments are gaining a lot of attention in the clinics thanks to their reduced invasiveness and their capability of treating non-surgical patients. The effectiveness of these treatments and their impact in the hospital's routine would significantly increase if paired with a monitoring technique able to control the evolution of the treated area in real-time. This is particularly relevant in microwave thermal ablation, wherein the capability of treating larger tumors in a shorter time needs proper monitoring. Current diagnostic imaging techniques do not provide effective solutions to this issue for a number of reasons, including economical sustainability and safety. Hence, the development of alternative modalities is of interest. Microwave tomography, which aims at imaging the electromagnetic properties of a target under test, has been recently proposed for this scope, given the significant temperature-dependent changes of the dielectric properties of human tissues induced by thermal ablation. In this paper, the outcomes of the first ex vivo experimental study, performed to assess the expected potentialities of microwave tomography, are presented. The paper describes the validation study dealing with the imaging of the changes occurring in thermal ablation treatments. The experimental test was carried out on two ex vivo bovine liver samples and the reported results show the capability of microwave tomography of imaging the transition between ablated and untreated tissue. Moreover, the discussion section provides some guidelines to follow in order to improve the achievable performances
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