161 research outputs found
Critical Lieb-Thirring bounds in gaps and the generalized Nevai conjecture for finite gap Jacobi matrices
We prove bounds of the form â_(eâIâĎ_d(H)) dist(e, Ď_e(H)^(1/2) ⤠L^1 -norm of a perturbation, where I is a gap. Included are gaps in continuum one-dimensional periodic SchrĂśdinger operators and finite gap Jacobi matrices, where we get a generalized Nevai conjecture about an L^(1)-condition implying a SzegĹ condition. One key is a general new form of the Birman-Schwinger bound in gaps
Condensation of fermion pairs in a domain
We consider a gas of fermions at zero temperature and low density,
interacting via a microscopic two body potential which admits a bound state.
The particles are confined to a domain with Dirichlet (i.e. zero) boundary
conditions. Starting from the microscopic BCS theory, we derive an effective
macroscopic Gross-Pitaevskii (GP) theory describing the condensate of fermion
pairs. The GP theory also has Dirichlet boundary conditions.
Along the way, we prove that the GP energy, defined with Dirichlet boundary
conditions on a bounded Lipschitz domain, is continuous under interior and
exterior approximations of that domain.Comment: 43 pages, 1 figur
Future Security Approaches and Biometrics
Threats to information security are proliferating rapidly, placing demanding requirements on protecting tangible and intangible business and individual assets. Biometrics can improve security by replacing or complementing traditional security technologies. This tutorial discusses the strengths and weaknesses of biometrics and traditional security approaches, current and future applications of biometrics, performance evaluation measures of biometric systems, and privacy issues surrounding the new technology
Proof of the Strong Scott Conjecture for Chandrasekhar Atoms
We consider a large neutral atom of atomic number Z, taking relativistic effects into account by assuming the dispersion relation âc²p²+câ´. We study the behavior of the one-particle ground state density on the length scale ZâťÂš in the limit Z,cââ keeping Z/c fixed and find that the spherically averaged density as well as all individual angular momentum densities separately converge to the relativistic hydrogenic ones. This proves the generalization of the strong Scott conjecture for relativistic atoms and shows, in particular, that relativistic effects occur close to the nucleus. Along the way we prove upper bounds on the relativistic hydrogenic density
The mindful path to compassion in an adult mental health group
A naturalistic study was undertaken within an NHS setting to explore the effectiveness and satisfaction with a Mindfulness-Based Cognitive Therapy and Mindful Self-Compassion group programme in an adult mental health population. Outcome measures and qualitative feedback suggested beneficial effects and high levels of satisfaction
Eigenvalue Bounds for Perturbations of SchrĂśdinger Operators and Jacobi Matrices With Regular Ground States
We prove general comparison theorems for eigenvalues of perturbed SchrĂśdinger operators that allow proof of LiebâThirring bounds for suitable non-free SchrĂśdinger operators and Jacobi matrices
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