Hawking radiation by Kerr black holes and conformal symmetry.

The exponential blueshift associated with the event horizon of a black hole makes conformal symmetry play a fundamental role in accounting for its thermal properties. Using a derivation based on two-point functions, we show that the full spectrum of thermal radiation of scalar particles by Kerr black holes can be explicitly derived on the basis of a conformal symmetry arising in the wave equation near the horizon. The simplicity of our approach emphasizes the depth of the connection between conformal symmetry and black hole radiance.

The prevalence of clinically relevant incidental findings on chest computed tomographic angiograms ordered to diagnose pulmonary embolism.

Background: Chest computed tomographic angiograms (CTAs) are frequently ordered for evaluation of suspected pulmonary embolism (PE) in the emergency department, but non-PE findings are often noted. Our objective was to determine the prevalence and management implications of incidental findings on chest CTAs ordered to assess for PE.

Methods: In a cross-sectional study, we reviewed 589 pulmonary CTAs that were ordered in the emergency department of a tertiary care hospital.

Revising the predictions of inflation for the cosmic microwave background anisotropies.

We point out that, if quantum field renormalization is taken into account and the counterterms are evaluated at the Hubble-radius crossing time or few e-foldings after it, the predictions of slow-roll inflation for both the scalar and the tensorial power spectrum change significantly. This leads to a change in the consistency condition that relates the tensor-to-scalar amplitude ratio with spectral indices. A reexamination of the potentials varphi;{2} and varphi;{4} shows that both are compatible with five-year WMAP data.

Reexamination of the power spectrum in de Sitter inflation.

We find that the amplitude of quantum fluctuations of the invariant de Sitter vacuum coincides exactly with that of the vacuum of a comoving observer for a massless scalar (inflaton) field. We propose redefining the actual physical power spectrum as the difference between the amplitudes of the above vacua. An inertial particle detector continues to observe the Gibbons-Hawking temperature.

Helical computed tomography inaccuracy in the detection of pulmonary metastases: can it be improved?

Background: In thoracic surgery, manual lung palpation for detection of pulmonary metastases during resection is the standard of care, despite improvements in computed tomography (CT) imaging. In our previous study based on chart review alone, the accuracy of helical CT in the detection of pulmonary metastases was surprisingly low, with a sensitivity of 78%. We hypothesized that this may be improved by scan interpretation with adequate clinical history and focused documentation of all pulmonary lesions, and may be influenced by the training of the reader.

Accuracy of helical CT in the detection of pulmonary metastases: is intraoperative palpation still necessary?

Background: Pulmonary metastasectomy is well accepted in patients with isolated metastases from an extrathoracic malignancy. The standard approach involves careful intraoperative palpation of the lungs because more metastases are frequently found than were seen by preoperative conventional computed tomography (CT). Helical CT detects more nodules than conventional CT, raising the question of whether palpation of the lungs is still necessary if helical CT is used.