13,029 research outputs found
A 4-sphere with non central radius and its instanton sheaf
We build an SU(2)-Hopf bundle over a quantum toric four-sphere whose radius
is non central. The construction is carried out using local methods in terms of
sheaves of Hopf-Galois extensions. The associated instanton bundle is presented
and endowed with a connection with anti-selfdual curvature.Comment: minor changes, appendix section extended. To appear in Letters in
Mathematical Physics. 22 pages, no figure
The quantum Cartan algebra associated to a bicovariant differential calculus
We associate to any (suitable) bicovariant differential calculus on a quantum
group a Cartan Hopf algebra which has a left, respectively right,
representation in terms of left, respectively right, Cartan calculus operators.
The example of the Hopf algebra associated to the differential calculus
on is described.Comment: 20 pages, no figures. Minor corrections in the example in Section 4
Increasing entanglement through engineered disorder in the random Ising chain
The ground state entanglement entropy between block of sites in the random
Ising chain is studied by means of the Von Neumann entropy. We show that in
presence of strong correlations between the disordered couplings and local
magnetic fields the entanglement increases and becomes larger than in the
ordered case. The different behavior with respect to the uncorrelated
disordered model is due to the drastic change of the ground state properties.
The same result holds also for the random 3-state quantum Potts model.Comment: 4 pages, published version, a few typos correcte
Segmented Strings in
We study segmented strings in flat space and in . In flat space, these
well known classical motions describe strings which at any instant of time are
piecewise linear. In , the worldsheet is composed of faces each of which
is a region bounded by null geodesics in an subspace of . The
time evolution can be described by specifying the null geodesic motion of kinks
in the string at which two segments are joined. The outcome of collisions of
kinks on the worldsheet can be worked out essentially using considerations of
causality. We study several examples of closed segmented strings in and
find an unexpected quasi-periodic behavior. We also work out a WKB analysis of
quantum states of yo-yo strings in and find a logarithmic term
reminiscent of the logarithmic twist of string states on the leading Regge
trajectory.Comment: 38 pages, 5 figure
Minimal Super Technicolor
We introduce novel extensions of the Standard Model featuring a
supersymmetric technicolor sector. First we consider N=4 Super Yang-Mills which
breaks to N=1 via the electroweak (EW) interactions and coupling to the MSSM.
This is a well defined, economical and calculable extension of the SM involving
the smallest number of fields. It constitutes an explicit example of a natural
supersymmetric conformal extension of the Standard Model featuring a well
defined connection to string theory. It allows to interpolate, depending on how
we break the underlying supersymmetry, between unparticle physics and Minimal
Walking Technicolor. As a second alternative we consider other N =1 extensions
of the Minimal Walking Technicolor model. The new models allow all the standard
model matter fields to acquire a mass.Comment: Improved version demonstrating that this extension is
phenomenologically viable. No Landau pole exists in the theory to two loops
level. This is the first theory showing that supersymmetry can solve the
flavor problem when coupled to low energy technicolo
Density Matrix Renormalization Group for Dummies
We describe the Density Matrix Renormalization Group algorithms for time
dependent and time independent Hamiltonians. This paper is a brief but
comprehensive introduction to the subject for anyone willing to enter in the
field or write the program source code from scratch.Comment: 29 pages, 9 figures. Published version. An open source version of the
code can be found at http://qti.sns.it/dmrg/phome.htm
Development and Role in Therapy of Canakinumab in Adult-Onset Still's Disease
Adult-onset Still's disease (AOSD) is a rare inflammatory disease of unknown etiology typically characterized by episodes of spiking fever, evanescent rash, arthralgia, leukocytosis, and hyperferritinemia. The pivotal role of interleukin (IL)-1 and other pro-inflammatory cytokines gives rise to the development of new targeted therapies. Currently, AOSD patients can benefit from efficient and well tolerated biologic agents, such as IL-1, IL-6, and tumour necrosis factor (TNF)-\u3b1 antagonists. Canakinumab, a human monoclonal anti-IL-1\u3b2 antibody, is indicated for the treatment of different autoinflammatory syndromes in adults, adolescents, and children and it has recently been approved for AOSD treatment. In this article, we summarize the structural and biochemical data describing the molecular interactions between Canakinumab and its target antigen. Some special considerations of the pharmacological properties of Canakinumab are included. We also review the safety, efficacy and tolerability of this drug for the treatment of AOSD
Entanglement properties of spin models in triangular lattices
The different quantum phases appearing in strongly correlated systems as well
as their transitions are closely related to the entanglement shared between
their constituents. In 1D systems, it is well established that the entanglement
spectrum is linked to the symmetries that protect the different quantum phases.
This relation extends even further at the phase transitions where a direct link
associates the entanglement spectrum to the conformal field theory describing
the former. For 2D systems much less is known. The lattice geometry becomes a
crucial aspect to consider when studying entanglement and phase transitions.
Here, we analyze the entanglement properties of triangular spin lattice models
by considering also concepts borrowed from quantum information theory such as
geometric entanglement.Comment: 19 pages, 8 figure
- …