Search results for "Anderson"
showing 10 items of 76 documents
Anderson-Fabry Disease: A Multiorgan Disease
2013
Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by a deficiency of the enzyme α-galactosidase A . FD causes glycolipids, such as globotriaosylceramide (Gb3), to accumulate in the vascular endothelium of several organs (fig.2), including the skin, kidneys, nervous system, and heart, thereby triggering inflammation and fibrosis . These processes generally result in organ dysfunction, which is usually the first clinical evidence of FD. Patients with classic FD have various symptoms, eg, acroparesthesias, hypohidrosis, angiokeratomas, corneal opacities, cerebrovascular lesions, cardiac disorders, andrenal dysfunction.However, evolving knowledge about the natural course o…
Quantum critical point in a periodic Anderson model
2000
We investigate the symmetric Periodic Anderson Model (PAM) on a three-dimensional cubic lattice with nearest-neighbor hopping and hybridization matrix elements. Using Gutzwiller's variational method and the Hubbard-III approximation (which corresponds to the exact solution of an appropriate Falicov-Kimball model in infinite dimensions) we demonstrate the existence of a quantum critical point at zero temperature. Below a critical value $V_c$ of the hybridization (or above a critical interaction $U_c$) the system is an {\em insulator} in Gutzwiller's and a {\em semi-metal} in Hubbard's approach, whereas above $V_c$ (below $U_c$) it behaves like a metal in both approximations. These prediction…
SPATIAL MULTIFRACTALITY OF ELECTRONIC STATES AND THE METAL-INSULATOR TRANSITION IN DISORDERED SYSTEMS
1993
For the investigation of the spatial behavior of electronic wave functions in disordered systems, we employ the Anderson model of localization. The eigenstates of the corresponding Hamiltonian are calculated numerically by means of the Lanczos algorithm and are analyzed with respect to their spatial multifractal properties. We find that the wave functions show spatial multifractality for all parameter cases not too far away from the metal-insulator transition (MIT) which separates localized from extended states in this model. Exactly at the MIT, multifractality is expected to exist on all length scales larger than the lattice spacing. It is found that the corresponding singularity spectrum…
Partial self-consistency and analyticity in many-body perturbation theory: Particle number conservation and a generalized sum rule
2016
We consider a general class of approximations which guarantees the conservation of particle number in many-body perturbation theory. To do this we extend the concept of $\Phi$-derivability for the self-energy $\Sigma$ to a larger class of diagrammatic terms in which only some of the Green's function lines contain the fully dressed Green's function $G$. We call the corresponding approximations for $\Sigma$ partially $\Phi$-derivable. A special subclass of such approximations, which are gauge-invariant, is obtained by dressing loops in the diagrammatic expansion of $\Phi$ consistently with $G$. These approximations are number conserving but do not have to fulfill other conservation laws, such…
VALUTAZIONE NON INVASIVA DELLA FUNZIONE ENDOTELIALE IN PAZIENTI AFFETTI DALLA MALATTIA DI ANDERSON-FABRY
2004
Fābri slimība Latvijā: fenotipa - genotipa korelācija
2017
Ievads. Andersona-Fābri slimība ir reta iedzimta lizosomālās uzkrāšanās slimība, ko izraisa mutācijas GLA gēnā un traucēta enzīmā α-galaktozidāzes A darbība. Līdz 2015. gadam Latvijā vēl nebija atklāts neviens pacients ar Fābri slimības diagnozi, bet šobrīd jau ir atrasti vairāk nekā 20 cilvēki ar GLA gēna mutācijām. Darba mērķi. Apkopot un analizēt klīnisko informāciju par Latvijā esošajiem pacientiem ar laboratoriski apstiprinātām mutācijām GLA gēnā, veidot šo datu statistisku pārskatu, kā arī raksturot noteiktu mutāciju radītās Fābri slimības fenotipiskās izpausmes un atrast iespējamas fenotipa-genotipa korelācijas. Darba metodes. Pētījumā iekļautas pilngadīgas personas ar ģenētiski apst…
Disorder-induced single-mode transmission.
2017
Localized states trap waves propagating in a disordered potential and play a crucial role in Anderson localization, which is the absence of diffusion due to disorder. Some localized states are barely coupled with neighbours because of differences in wavelength or small spatial overlap, thus preventing energy leakage to the surroundings. This is the same degree of isolation found in the homogeneous core of a single-mode optical fibre. Here we show that localized states of a disordered optical fibre are single mode: the transmission channels possess a high degree of resilience to perturbation and invariance with respect to the launch conditions. Our experimental approach allows identification…
Korelētas nesakārtotības ietekme uz lokalizācijas parādību viendimensionālos ciešās saites modeļos
2021
Darbā pētīta Andersona modeļa pamatstāvokļa lokalizācija vienā dimensijā, izmantojot ciešās saites tuvinājumu. Tika veikta padziļināta korelācijas un nesakārtotības ietekmes uz lokalizācijas parādību izpēte. Pētījuma veikšanai tika izveidoti skaitliski modeļi un veikti analītiski aprēķini. Darbā tika noskaidrots, ka korelācija kvalitatīvi izmaina lokalizācijas parādību, un tika aprēķinātas lokalizācijas garuma kritiskās eksponentes pie dažādām korelācijas pakāpēm.