15,512 research outputs found
[Review of] Mariama Ba. So Long A Letter
So Long A Letter is the story of Ramatoulaye, a recently-widowed Sengalese [Senegalese] woman, as she writes to her long-time friend Aissatou. It is the articulate, often anguished narrative of a Muslim woman faced with the sudden second marriage of her husband of twenty-five years. Although polygamy is accepted by her religion and her society, Ramatoulaye feels rejected and betrayed. Yet she chooses to remain in her marriage and prepares to share equally her husband with her new co-wife, as dictated by Muslim law. Her husband, however, abandons her completely, to manage their twelve children alone. Upon his death five years later, she is faced not only with grief and confused emotion but also with enormous debts he compiled in wooing his new young wife and her greedy mother. Ramatoulaye\u27s dignity and quiet strength overcome her bitterness and pain, and she is able to begin forging her own happiness again while responding to her family\u27s changing needs
Light Stop Searches at the LHC in Events with One Hard Photon or Jet and Missing Energy
Low energy supersymmetric models provide a solution to the hierarchy problem
and also have the necessary ingredients to solve two of the most outstanding
issues in cosmology: the origin of the baryon asymmetry and the source of dark
matter. In the MSSM, weak scale generation of the baryon asymmetry may be
achieved in the presence of light stops, with masses lower than about 130 GeV.
Moreover, the proper dark matter density may be obtained in the stop-neutralino
co-annihilation region, where the stop-neutralino mass difference is smaller
than a few tens of GeV. Searches for scalar top quarks (stops) in pair
production processes at the Tevatron and at the Large Hadron Collider (LHC)
become very challenging in this region of parameters. At the LHC, however,
light stops proceeding from the decay of gluino pairs may be identified,
provided the gluino mass is smaller than about 900 GeV. In this article we
propose an alternative method for stop searches in the co-annihilation region,
based on the search for these particles in events with missing energy plus one
hard photon or jet. We show that this method is quite efficient and, when
complemented with ongoing Tevatron searches, allows to probe stop masses up to
about 160 GeV, fully probing the region of parameters consistent with
electroweak baryogenesis in the MSSM.Comment: 17 pages, 6 figure
Comment on "Effective of the q-deformed pseudoscalar magnetic field on the charge carriers in graphene"
We point out a misleading treatment in a recent paper published in this
Journal [J. Math. Phys. (2016) 57, 082105] concerning solutions for the
two-dimensional Dirac-Weyl equation with a q-deformed pseudoscalar magnetic
barrier. The authors misunderstood the full meaning of the potential and made
erroneous calculations, this fact jeopardizes the main results in this system.Comment: 7 pages, 2 figure
A Random Multifractal Tilling
We develop a multifractal random tilling that fills the square. The
multifractal is formed by an arrangement of rectangular blocks of different
sizes, areas and number of neighbors. The overall feature of the tilling is an
heterogeneous and anisotropic random self-affine object. The multifractal is
constructed by an algorithm that makes successive sections of the square. At
each -step there is a random choice of a parameter related to the
section ratio. For the case of random choice between and we
find analytically the full spectrum of fractal dimensions
Anisotropy and percolation threshold in a multifractal support
Recently a multifractal object, , was proposed to study percolation
properties in a multifractal support. The area and the number of neighbors of
the blocks of show a non-trivial behavior. The value of the
probability of occupation at the percolation threshold, , is a function
of , a parameter of which is related to its anisotropy. We
investigate the relation between and the average number of neighbors of
the blocks as well as the anisotropy of
A lower bound to the spectral threshold in curved tubes
We consider the Laplacian in curved tubes of arbitrary cross-section rotating
together with the Frenet frame along curves in Euclidean spaces of arbitrary
dimension, subject to Dirichlet boundary conditions on the cylindrical surface
and Neumann conditions at the ends of the tube. We prove that the spectral
threshold of the Laplacian is estimated from below by the lowest eigenvalue of
the Dirichlet Laplacian in a torus determined by the geometry of the tube.Comment: LaTeX, 13 pages; to appear in R. Soc. Lond. Proc. Ser. A Math. Phys.
Eng. Sc
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