1,980 research outputs found
Asymmetrical bloch branes and the hierarchy problem
We investigate a two scalar fields split braneworld model which leads to a
possible approach to the hierarchy problem within the thick brane scenario. The
model exhibits a resulting asymmetric warp factor suitable for this purpose.
The solution is obtained by means of the orbit equation approach for a specific
value of one of the parameters. Besides, we analyze the model qualitative
behaviour for arbitrary parameters by inspecting the underlying dynamical
system defined by the equations which give rise to the braneworld model. We
finalize commenting on the metric fluctuation and stability issues.Comment: 8 pages, 7 figure
High Spatial Resolution of the Mid-Infrared Emission of Compton-Thick Seyfert 2 Galaxy Mrk3
Mid-infrared (MIR) spectra observed with Gemini/Michelle were used to study
the nuclear region of the Compton-thick Seyfert 2 (Sy 2) galaxy Mrk 3 at a
spatial resolution of 200 pc. No polycyclic aromatic hydrocarbons (PAHs)
emission bands were detected in the N-band spectrum of Mrk 3. However, intense
[Ar III] 8.99 m, [S IV] 10.5 m and [Ne II] 12.8 m ionic
emission-lines, as well as silicate absorption feature at 9.7m have been
found in the nuclear extraction (200 pc). We also present
subarcsecond-resolution Michelle N-band image of Mrk 3 which resolves its
circumnuclear region. This diffuse MIR emission shows up as a wings towards
East-West direction closely aligned with the S-shaped of the Narrow Line Region
(NLR) observed at optical [O III]5007\AA image with Hubble/FOC. The
nuclear continuum spectrum can be well represented by a theoretical torus
spectral energy distribution (SED), suggesting that the nucleus of Mrk 3 may
host a dusty toroidal structure predicted by the unified model of active
galactic nucleus (AGN). In addition, the hydrogen column density
(N cm) estimated with a torus
model for Mrk 3 is consistent with the value derived from X-ray spectroscopy.
The torus model geometry of Mrk 3 is similar to that of NGC 3281, both
Compton-thick galaxies, confirmed through fitting the 9.7m silicate band
profile. This results might provide further evidence that the silicate-rich
dust can be associated with the AGN torus and may also be responsible for the
absorption observed at X-ray wavelengths in those galaxies.Comment: 11 pages, 6 figure
Remarks on supersymmetry of quantum systems with position-dependent effective masses
We apply the supersymmetry approach to one-dimensional quantum systems with
spatially-dependent mass, by including their ordering ambiguities dependence.
In this way we extend the results recently reported in the literature.
Furthermore, we point out a connection between these systems and others with
constant masses. This is done through convenient transformations in the
coordinates and wavefunctions.Comment: 8 pages, 1 figur
Hematoma Cervical Secundário a Hemorragia Espontânea da Tiroide
Spontaneous thyroid haemorrhage is rare, but it can be a potentially life-threatening condition in severe cases, due to acute upper airway compromise.
We report the case of a 75-year-old patient on chronic anticoagulation therapy for atrial fibrillation, who presented with sudden painful neck bulging and dysphagia. Physical examination revealed a hard mass on the anterior left side of the neck. Preliminary laryngoscopy was normal. The diagnosis was made using ultrasonography and further characterization with computed tomography, showing haemorrhage of a thyroid nodule with capsular disruption and diffusion of the haematoma to the deep cervical spaces, causing important tracheal deviation and hypopharynx compression. The patient developed dyspnoea and ultimately required urgent hemithyroidectomy.
This case also highlights the importance of having a high index of clinical suspicion and prompt imaging in patients with atypical presentations of a neck mass.info:eu-repo/semantics/publishedVersio
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