Analytic Continuation of Resolvent Kernels on noncompact Symmetric Spaces

Let X=G/K be a symmetric space of noncompact type and let L be the Laplacian associated with a G-invariant metric on X. We show that the resolvent kernel of L admits a holomorphic extension to a Riemann surface depending on the rank of the symmetric space. This Riemann surface is a branched cover of the complex plane with a certain part of the real axis removed. It has a branching point at the bottom of the spectrum of L. It is further shown that this branching point is quadratic if the rank of X is odd, and is logarithmic otherwise. In case G has only one conjugacy class of Cartan subalgebras the resolvent kernel extends to a holomorphic function on a branched cover of the complex plane with the only branching point being the bottom of the spectrum.Comment: 16 pages, 3 figures, LaTe

SANTRAUKOS

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High-contrast dark resonance on the D2 - line of 87Rb in a vapor cell with different directions of the pump - probe waves

We propose a novel method enabling to create a high-contrast dark resonance in the 87Rb vapor D2-line. The method is based on an optical pumping of atoms into the working states by a two-frequency, linearly-polarized laser radiation propagating perpendicularly to the probe field. This new scheme is compared to the traditional scheme involving the circularly-polarized probe beam only, and significant improvement of the dark resonance parameters is found. Qualitative considerations are confirmed by numerical calculations.Comment: 7 pages, 4 figure

I giovani a bassa scolarità in due quartieri torinesi

Working Paper ; n.104- Indice #3- Giovani a bassa scolarità a Torino: un problema degli anni '90 #5- Lavoro e scolarità nei giovani torinesi #7- Giovani a bassa scolarità nei quartieri S.Donato e Regio Parco #23- Approfondimenti. I giovani e la scuola #33- I giovani nel quartiere San Donato #35- I giovani el quartiere Regio Parco/Barca/Bertolla #53- La scuola a S. Donato #65- La scuola a Regio Parco/Barca/Bertola #89- Appendice: le circoscrizioni di riferimento #10

Bergers des plains de Léon [Material gráfico]= Shepherds of the plains of León

Lámina coloreada al aguatintaCopia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Scaling of the spin stiffness in random spin-1/2 chains : Crossover from pure-metallic behaviour to random singlet-localized regime

In this paper we study the localization transition induced by the disorder in random antiferromagnetic spin-1/2 chains. The results of numerical large scale computations are presented for the XX model using its free fermions representation. The scaling behavior of the spin stiffness is investigated for various disorder strengths. The disorder dependence of the localization length is studied and a comparison between numerical results and bosonization arguments is presented. A non trivial connection between localization effects and the crossover from the pure XX fixed point to the infinite randomness fixed point is pointed out.Comment: Published version, 7 pages, 6 figure

A student of the Irish College, Salamanca [Material gráfico]

Lámina coloreada al aguatintaCopia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2010-201

Intérieur de l'Église de St. Dominique de Salamanque [Material gráfico]= Interior of the Dominican Church, Salamanca

Lámina coloreada al aguatintaCopia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Secure direct communication using Einstein-Podolsky-Rosen pairs and teleportation

A novel scheme for secure direct communication between Alice and Bob is proposed, where there is no need for establishing a shared secret key. The communication is based on Einstein-Podolsky-Rosen pairs and teleportation between Alice and Bob. After insuring the security of the quantum channel (EPR pairs), Bob encodes the secret message directly on a sequence of particle states and transmits them to Alice by teleportation. In this scheme teleportation transmits Bob's message without revealing any information to a potential eavesdropper. Alice can read out the encoded messages directly by the measurement on her qubits. Because there is not a transmission of the qubit which carry the secret message between Alice and Bob, it is completely secure for direct secret communication if perfect quantum channel is used

Paysan en habit de paille [Material gráfico]= Peasant in a straw coat

Lámina coloreada al aguatintaCopia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201