Unexpected behavior of the cca transition operators under particle interchange

2008 ◽  
pp. 185-186
Author(s):  
F. S. Levin ◽  
H. Krüger
Keyword(s):  
Transition Operators ◽  
Unexpected Behavior

A NOTE ON THE NORMS OF TRANSITION OPERATORS ON LAMPLIGHTER GRAPHS AND GROUPS

2005 ◽  
Vol 15 (05n06) ◽  
pp. 1261-1272 ◽  
Author(s):  
WOLFGANG WOESS
Keyword(s):  
Random Walk ◽  
Wreath Products ◽  
Locally Compact Group ◽  
Operator Matrix ◽  
Locally Compact ◽  
Finitely Generated Groups ◽  
Group Of Isometries ◽  
Transition Operators ◽  
Special Case ◽  
Product Of Groups

Let L≀X be a lamplighter graph, i.e., the graph-analogue of a wreath product of groups, and let P be the transition operator (matrix) of a random walk on that structure. We explain how methods developed by Saloff-Coste and the author can be applied for determining the ℓp-norms and spectral radii of P, if one has an amenable (not necessarily discrete or unimodular) locally compact group of isometries that acts transitively on L. This applies, in particular, to wreath products K≀G of finitely-generated groups, where K is amenable. As a special case, this comprises a result of Żuk regarding the ℓ2-spectral radius of symmetric random walks on such groups.

Unexpected behavior of transient current in thin PZT films caused by grain-boundary conduction

2017 ◽  
Vol 121 (22) ◽  
pp. 224104 ◽  
Author(s):  
L. A. Delimova ◽  
E. V. Guschina ◽  
D. S. Seregin ◽  
K. A. Vorotilov ◽  
A. S. Sigov
Keyword(s):  
Grain Boundary ◽  
Transient Current ◽  
Pzt Films ◽  
Unexpected Behavior ◽  
Boundary Conduction

UNEXPECTED BEHAVIOR IN THE CROSSING OF MICROWAVE AND OPTICAL BEAMS

2005 ◽  
Vol 19 (27) ◽  
pp. 1403-1410 ◽  
Author(s):  
E. ALLARIA ◽  
R. MEUCCI ◽  
D. MUGNAI ◽  
A. RANFAGNI ◽  
C. RANFAGNI
Keyword(s):  
Lorentz Invariance ◽  
Point Of View ◽  
Experimental Results ◽  
Light Velocity ◽  
Broken Lorentz Invariance ◽  
Points Of View ◽  
Optical Beams ◽  
Definite Solution ◽  
Unexpected Behavior

The question of the superluminal speed of information was stopped at crossroads in the last few years. According to one point of view, this speed must be limited to the light velocity in vacuum, whereas a different point of view is more open in this respect and, under specific conditions, this limit is considered surmountable. Very recently, a third approach (based on the hypothesis of a local broken Lorentz-invariance) was proposed and, if confirmed, would go beyond the controversy of the two points of view mentioned above. It is therefore worthwhile to recall attention to this problem, which is far from having a definite solution. The present paper reports some experimental results (similar to those of Ref. 1) which can contribute to these discussions, and also considers the fact that they seem to give some support to the aforesaid third approach, although revised in terms of decaying waves.

POSITIVE MAGNETO-RESISTANCE IN A POINT CONTACT: POSSIBLE MANIFESTATION OF INTERACTIONS

2007 ◽  
Vol 17 (03) ◽  
pp. 495-499
Author(s):  
V. T. RENARD ◽  
T. OTA ◽  
N. KUMADA ◽  
H. HIRAYAMA
Keyword(s):  
Point Contact ◽  
Quantum Point Contacts ◽  
Point Contacts ◽  
Temperature Dependent ◽  
Quantum Point ◽  
Magneto Resistance ◽  
Unexpected Behavior ◽  
Electron Interactions

We report a non-monotonic and strongly temperature dependent magneto-resistance observed in clean quantum point contacts. At the same time the conductance of the point contact varies linearly with temperature. This unexpected behavior may be related to electron-electron interactions.

scholarly journals Характер изменения обратного тока в туннельных МДП-диодах с фторидом кальция на Si(111) при создании дополнительного оксидного слоя

2019 ◽  
Vol 53 (6) ◽  
pp. 844
Author(s):  
А.Г. Банщиков ◽  
Ю.Ю. Илларионов ◽  
М.И. Векслер ◽  
S. Wachter ◽  
Н.С. Соколов
Keyword(s):  
Reverse Bias ◽  
Simulation Data ◽  
Voltage Range ◽  
Unexpected Behavior

AbstractThe currents flowing in metal–CaF_2– n -Si and metal–SiO_2–CaF_2– n -Si structures with the same (about 1.5 nm) fluoride thickness are compared in the reverse-bias mode. It is revealed that the current in the case of a two-layer dielectric can be notably higher within a certain voltage range. Such unexpected behavior is associated with the coexistence of both electron and hole components of the current as well as with the configuration of the SiO_2–CaF_2 barrier through which tunneling occurs. The results of measurements and explanatory simulation data are presented.

scholarly journals Heck-Type Coupling of Fused Bicyclic Vinylcyclopropanes: Synthesis of 1,2-Dihydropyridines, 2,3-Dihydro-1H-Azepines, 1,4-Cyclohexadienes, 2H-Pyrans, and 1,3-Butadienes

2021 ◽  
Author(s):  
Nikolai Wurzer ◽  
Urszula Klimczak ◽  
Tobias Babl ◽  
Sebastian Fischer ◽  
Ricardo A. Angnes ◽  
...  
Keyword(s):  
Heck Reaction ◽  
Ring Opening ◽  
Theoretical Calculations ◽  
Ring Expansion ◽  
Mechanistic Studies ◽  
Type Coupling ◽  
Hydride Elimination ◽  
Unexpected Behavior

Herein, we report a versatile approach for the endocyclic ring-opening of bicyclic vinylcyclopropanes triggered by Heck arylations. Key step for this transformation is a [1,3]-migratory shift of Pd allowing the ring expansion of cyclopropanated pyrroles, piperidines, furans as well as cyclopentadienes to grant access to the corresponding 1,2-dihydropyridines, 2<i>H</i>-pyrans, 2,3-dihydro-1<i>H</i>-azepines and 1,4-cyclohexadienes, respectively. Additionally, <i>gem</i>-disubstituted cyclopropanated furans showed unexpected behavior by giving diastereoselectively asymmetrically substituted dienes. Mechanistic studies and theoretical calculations point towards a facile [1,3]-migratory shift of Pd along the cyclopropane moiety, which can successfully compete with the usual termination step of a Heck reaction via a <i>syn</i>-b-hydride elimination.<br>

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