Non-minimal Maxwell-Chern-Simons theory and the composite Fermion model

The magnetic field redefinition in Jain's composite fermion model for the fractional quantum Hall effect is shown to be effectively described by a mean-field approximation of a model containing a Maxwell-Chern-Simons gauge field non-minimally coupled to matter. Also an explicit non-relativistic limit of the non-minimal (2+1)D Dirac equation is derived.Comment: 10 pages, no figure

Planar Supersymmetric Quantum Mechanics of a Charged Particle in an External Electromagnetic Field

The supersymmetric quantum mechanics of a two-dimensional non-relativistic particle subject to external magnetic and electric fields is studied in a superfield formulation and with the typical non-minimal coupling of (2+1) dimensions. Both the N=1 and N=2 cases are contemplated and the introduction of the electric interaction is suitably analysed.Comment: V3-Improved by Referees' sugestions. REVTeX4 6 pages (twocolumn option), no figures. V2-Minor changes. A previous version of this work was presented by JAHN during the II Intern. Conf. on Fundamental Interactions, June 2004, Pedra Azul-ES, Brazil. Submitted to Phys. Rev.

Supersymmetry and Integrability in Planar Mechanical Systems

We present an N=2-supersymmetric mechanical system whose bosonic sector, with two degrees of freedom, stems from the reduction of an SU(2) Yang-Mills theory with the assumption of spatially homogeneous field configurations and a particular ansatz imposed on the gauge potentials in the dimensional reduction procedure. The Painleve test is adopted to discuss integrability and we focus on the role of supersymmetry and parity invariance in two space dimensions for the attainment of integrable or chaotic models. Our conclusion is that the relationships among the parameters imposed by supersymmetry seem to drastically reduce the number of possibilities for integrable interaction potentials of the mechanical system under consideration.Comment: 20 pages, 3 figure

CsCuCl3 perovskite-like compound under extreme conditions

Halide perovskite has attracted intense research interest owing to its multifaceted and versatile applications in optoelectronics. This intrigue is further fueled by their propensity to undergo intricate structural modifications under extreme conditions, thereby instigating property changes. Within this context, our study delves deep into the intricate interplay of structural and vibrational attributes within the inorganic-metal halide perovskite-like CsCuCl3. Our approach employs Raman spectroscopy and Synchrotron Powder X-Ray Diffraction (SPXRD) techniques harnessed under the dual conditions of low temperatures and high pressures. We have observed a distinct spin-phonon coupling mechanism by employing Raman spectroscopy at low temperatures; this coupling has been manifested as a renormalization phonon phenomenon that occurs notably at T* = 15 K. The correlation between spin and phonon dynamics becomes pronounced through a notable hardening of phonon temperature dependence, a behavior intricately linked to the material antiferromagnetic transition at TN = 10.7 K. The SPXRD under high pressure showed a first-order structural phase transition (SPT) at the critical pressure Pc = 3.69 GPa, leading to the transformation from the hexagonal P6522 to a base-centered monoclinic cell. Notably, the coexistence of both phases is discernible within the pressure range from 2.79 to 3.57 GPa, indicating that the SPT involves the reorganization of the internal [Cu2Cl9]5- dimer unit, with the Cl-Cu-Cl bending contributing more than stretching modes. Furthermore, we demonstrate that the SPT is reversible, but residual strain pressure influences the modification of the critical pressure Pc value upon pressure decrease.Comment: 27 pages, 8 figure

Intradural tumors

History of Spinal Disorders.- Basic Science: Biomechanics of the Spine.- Spinal Instrumentation.- Age-Related Changes of the Spine.- Pathways of Spinal Pain.- Epidemiology and Risk Factors of Spinal Disorders.- Predictors of Surgical Outcome.- Patient Assessment: History and Physical Examination.- Imaging Studies.- Spinal Injections.- Neurological Assessment in Spinal Disorders.- Neurophysiological Investigations.- Surgical Approaches.- Peri- and Postoperative Management: Preoperative Assessment.- Intraoperative Anaestesia Management.- Postoperative Care and Pain Management.- Degenerative Disorders: Degenerative Disorders of the Cervical Spine.- Disc Herniation and Radiculopathy.- Lumbar Spinal Stenosis.- Degenerative Lumbar Spondylosis.- Non-specific Low Back Pain.- Postoperative Rehabilitation.- Spinal Deformities and Malformations: Idiopathic Scoliosis.- Neuromuscular Scoliosis.- Congenital Scoliosis.- Degenerative Scoliosis.- Spondylolisthesis.- Juvenile Kyphosis (Scheuermann's Disease).- Malformations of the Spinal Cord.- Fractures: Cervical Spine Injuries.- Thoracolumbar Spinal Injuries.- Osteoporotic Spine Fractures.- Tumor and Inflammation: Primary Tumors of the Spine.- Spinal Metastasis.- Intradural Tumors.- Infections of the Spine.- Rheumatoid Arthritis.- Ankylosing Spondylitis.- Treatment of Postoperative Complications.- Outcome Questionnaires and Tools in Spinal Surgery