5,389 research outputs found
Cerebrospinal Fluid: Novel Developed Biomarkers in Neurological Disease
No full textCerebrospinal Fluid: Novel Developed Biomarkers in Neurological Disease
(M. Dessi, F. Duranti, M. Pieri, G. Sancesario, R. Zenobi, S. Bernardini, Department of Experimental Medicine and Surgery, “Tor Vergata” University Hospital, Rome, Italy)pp.15-6
Quantum cohomology of the odd symplectic Grassmannian of lines
Get PDFOdd symplectic Grassmannians are a generalization of symplectic Grassmannians to odd-dimensional spaces. Here we compute the classical and quantum cohomology of the odd
symplectic Grassmannian of lines. Although these varieties are not homogeneous, we obtain Pieri and Giambelli formulas that are very similar to the symplectic case. We notice that their quantum cohomology is semi-simple, which enables us to check Dubrovin’s conjecture for this case
Kraśkiewicz-Pragacz Modules and Pieri and Dual Pieri Rules for Schubert Polynomials
No full textIn their 1987 paper Kra\\u27skiewicz and Pragacz defined certain modules \smod_w (), which we call KP modules, over the upper triangular Lie algebra whose characters are Schubert polynomials. In a previous work the author showed that the tensor product of KP modules always has a KP filtration, i.e. a filtration whose each successive quotients are isomorphic to KP modules. In this paper we explicitly construct such filtrations for certain special cases of these tensor product modules, namely \smod_w \otimes S^d(K^i) and \smod_w \otimes \bigwedge^d(K^i), corresponding to Pieri and dual Pieri rules for Schubert polynomials
Bose-Fermi mixtures with pairing
Get PDFI will review recent work by us on the properties of Bose-Fermi mixtures with a tunable pairing interaction
between bosons and fermions. A many-body diagrammatic approach, able to describe the condensed phase of
a Bose-Fermi mixture from weak to strong boson-fermion couplings, will be presented [1]. This approach will
be validated by comparing it with previous [2] and new dedicated fixed-node diffusion Monte Carlo
calculations. By using both methods, a universal behavior of the condensate fraction and bosonic momentum
distribution with respect to the boson concentration is found in an extended range of boson-fermion couplings
and concentrations. For vanishing boson density, the bosonic condensate fraction reduces to the quasiparticle
weight Z of the Fermi polaron studied in the context of polarized Fermi gases, unifying in this way two
apparently unrelated quantities. Finally, I will discuss an interesting effect occurring in the molecular limit of
the boson- fermion coupling, where the condensation is completely suppressed [3]. This phenomenon is an
indirect effect on bosons of the Pauli exclusion principle acting on fermions, and is the counterpart in BoseFermi
mixtures of the so called “Sarma phase” discussed for polarized Fermi gases.
[1] A. Guidini, G. Bertaina, D. Galli, and P. Pieri, arXiv:1412.2542.
[2] G. Bertaina, E. Fratini, S. Giorgini, and P. Pieri, Phys. Rev. Lett. 110, 115303 (2013).
[3] A. Guidini, G. Bertaina, E. Fratini, and P. Pieri, Phys. Rev. A 89, 023634 (2014)
Pairing effects in the normal phase of a two-dimensional Fermi gas
No full textIn recent experiments [1, 2], a pairing gap was detected in a two-dimensional (2D)
Fermi gas with attractive interaction at temperatures where superfluidity does not occur.
A relevant question is whether this gap is a pseudogap phenomenon or is due to a molecular
state, which is always present in 2D. In this talk I will discuss how the boundary between
the pseudogap and molecular regimes can be set, and compare the theoretical results
obtained by using a t-matrix approach [3] with the above experimental data for a 2D
Fermi gas. I will also show that pseudogap phenomena occurring in 2D and 3D can be
related through a variable spanning the BCS-BEC crossover in a universal way.
[1] M. Feld, B. Fr ̈ohlich, E. Vogt, M. Koschorreck, and M. K ̈ohl, Nature 480, 75 (2011).
[2] P. A. Murthy, M. Neidig, R. Klemt, L. Bayha, I. Boettcher, T. Enss, M. Holten, G. Z ̈urn,
P. M. Preiss, and S. Jochim, arXiv:1705.10577 (2017).
[3] F. Marsiglio, P. Pieri, A. Perali, F. Palestini, and G. C. Strinati, Phys. Rev. B 91, 054509
(2015
Affine Pieri rule for periodic Macdonald spherical functions and fusion rings
No full textLet gˆ be an untwisted affine Lie algebra or the twisted counterpart thereof (which excludes the affine Lie algebras of type BCˆn=A2n(2)). We present an affine Pieri rule for a basis of periodic Macdonald spherical functions associated with gˆ. In type Aˆn−1=An−1(1) the formula in question reproduces an affine Pieri rule for cylindric Hall-Littlewood polynomials due to Korff, which at t=0 specializes in turn to a well-known Pieri formula in the fusion ring of genus zero slˆ(n)c-Wess-Zumino-Witten conformal field theories.Applied Probabilit
Pieri rule for the affine flag variety
No full textWe prove the affine Pieri rule for the cohomology of the affine flag variety conjectured by Lam, Lapointe, Morse and Shimozono. We study the cap operator on the affine nilHecke ring that is motivated by Kostant and Kumar's work on the equivariant cohomology of the affine flag variety. We show that the cap operators for Pieri elements are the same as Pieri operators defined by Berg, Saliola and Serrano. This establishes the affine Pieri rule. We also discuss properties of cap operators which are not necessarily affine A type. © 2016 Elsevier Inc.N
Kraskiewicz-Pragacz modules and Pieri and dual Pieri rules for Schubert polynomials
Get PDFIn their 1987 paper Kraskiewicz and Pragacz defined certain modules, which we call KP modules, over the upper triangular Lie algebra whose characters are Schubert polynomials. In a previous work the author showed that the tensor product of Kraskiewicz-Pragacz modules always has KP filtration, i.e. a filtration whose each successive quotients are isomorphic to KP modules. In this paper we explicitly construct such filtrations for certain special cases of these tensor product modules, namely Sw Sd(Ki) and Sw Vd(Ki), corresponding to Pieri and dual Pieri rules for Schubert polynomials
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