Aberrational Effects for Shadows of Black Holes

In this paper, we discuss how the shadow of a Kerr black hole depends on the motion of the observer. In particular, we derive an analytical formula for the boundary curve of the shadow for an observer moving with given four-velocity at given Boyer--Lindquist coordinates. We visualize the shadow for various values of parameters.Comment: 12 pages, 3 figures; Proceedings of the 524. WE-Heraeus-Seminar held at the Physikzentrum, Bad Honnef, Germany, 17.--23.2.201

Effect of Disorder on Fermi surface in Heavy Electron Systems

The Kondo lattice model with substitutional disorder is studied with attention to the size of the Fermi surface and the associated Dingle temperature. The model serves for understanding heavy-fermion Ce compounds alloyed with La according to substitution Ce{x}La{1-x}. The Fermi surface is identified from the steepest change of the momentum distribution of conduction electrons, and is derived at low enough temperature by the dynamical mean-field theory (DMFT) combined with the coherent potential approximation (CPA). The Fermi surface without magnetic field increases in size with decreasing x from x=1 (Ce end), and disappears at such x that gives the same number of localized spins as that of conduction electrons. From the opposite limit of x=0 (La end), the Fermi surface broadens quickly as x increases, but stays at the same position as that of the La end. With increasing magnetic field, a metamagnetic transition occurs, and the Fermi surface above the critical field changes continuously across the whole range of x. The Dingle temperature takes a maximum around x=0.5. Implication of the results to experimental observation is discussed.Comment: 5 pages, 5 figure

Symptomatic Oculomotor Nerve Cyst in a 3-Year-Old Child: Case Report With Emphasis on Surgical Management

Background and Importance: Third nerve palsies in the pediatric population are most commonly caused by trauma, tumors, or vascular abnormalities. Cystic oculomotor nerve neuropathies, however, are rare. We report the case of a symptomatic cyst along and within the oculomotor nerve, which has not been described previously. Clinical Presentation: Here, we report a case of a 3-yr-old girl presenting with a progressive painless oculomotor nerve palsy. A magnetic resonance imaging revealed a cystic formation along the cisternal and cavernous course of the nerve. Due to lack of alternative treatment options, surgery was offered. Intraoperative direct nerve stimulation allowed for identification of a non-functional part of the cyst wall and open fenestration and biopsy were executed. Histopathology revealed neuritis. Serology was negative for various pathogens. The oculomotor palsy rapidly resolved. At a follow-up 5 yr after surgery, the girl is asymptomatic and the cisternal part of the cyst remains collapsed. Conclusion: This is the first report of a symptomatic cyst along and within the oculomotor nerve treated effectively with open fenestration and decompression highlighting the importance of intraoperative neuromonitoring in cranial nerve surgery. Uncertainty remains regarding the etiology of this disease