315 research outputs found
Modern cosmologies from empty Kaluza-Klein solutions in 5D
We show that the empty five-dimensional solutions of
Davidson-Sonnenschtein-Vozmediano, {\em Phys. Rev.} {\bf D32} (1985)1330, in
the "old" Kaluza-Klein gravity, under appropriate interpretation can generate
an ample variety of cosmological models in 4D, which include the
higher-dimensional modifications to general relativity predicted by "modern"
versions of noncompactified 5D gravity as, e.g., induced-matter and braneworld
theories. This is the first time that these solutions are investigated in a
systematic way as embeddings for cosmological models in 4D. They provide a
different formulation, which is complementary to the approaches used in current
versions of 5D relativity.Comment: Accepted for publication in JHE
Stochastic emergence of inflaton fluctuations in a SdS primordial universe with large-scale repulsive gravity from a 5D vacuum
We develop a stochastic approach to study scalar field fluctuations of the
inflaton field in an early inflationary universe with a black-hole (BH), which
is described by an effective 4D SdS metric. Considering a 5D Ricci-flat SdS
static metric, we implement a planar coordinate transformation, in order to
obtain a 5D cosmological metric, from which the effective 4D SdS metric can be
induced on a 4D hypersurface. We found that at the end of inflation, the
squared fluctuations of the inflaton field are not exactly scale independent
and becomes sensitive with the mass of the BH.Comment: version accepted in European Physical Journal Plu
Static wormholes on the brane inspired by Kaluza-Klein gravity
We use static solutions of 5-dimensional Kaluza-Klein gravity to generate
several classes of static, spherically symmetric spacetimes which are analytic
solutions to the equation , where is the
four-dimensional Ricci scalar. In the Randall & Sundrum scenario they can be
interpreted as vacuum solutions on the brane. The solutions contain the
Schwarzschild black hole, and generate new families of traversable Lorenzian
wormholes as well as nakedly singular spacetimes. They generalize a number of
previously known solutions in the literature, e.g., the temporal and spatial
Schwarzschild solutions of braneworld theory as well as the class of self-dual
Lorenzian wormholes. A major departure of our solutions from Lorenzian
wormholes {\it a la} Morris and Thorne is that, for certain values of the
parameters of the solutions, they contain three spherical surfaces (instead of
one) which are extremal and have finite area. Two of them have the same size,
meet the "flare-out" requirements, and show the typical violation of the energy
conditions that characterizes a wormhole throat. The other extremal sphere is
"flaring-in" in the sense that its sectional area is a local maximum and the
weak, null and dominant energy conditions are satisfied in its neighborhood.
After bouncing back at this second surface a traveler crosses into another
space which is the double of the one she/he started in. Another interesting
feature is that the size of the throat can be less than the Schwarzschild
radius , which no longer defines the horizon, i.e., to a distant observer
a particle or light falling down crosses the Schwarzschild radius in a finite
time
The bang of a white hole in the early universe from a 6D vacuum state: Origin of astrophysical spectrum
Using a previously introduced model in which the expansion of the universe is
driven by a single scalar field subject to gravitational attraction induced by
a white hole during the expansion (from a 6D vacuum state), we study the origin
of squared inflaton fluctuations spectrum on astrophysical scales.Comment: Final version to be published in Eur. Phys. J.
A 5D non compact and non Ricci flat Kaluza-Klein Cosmology
A model universe is proposed in the framework of 5-dimensional noncompact
Kaluza-Klein cosmology which is not Ricci flat. The 4D part as the
Robertson-Walker metric is coupled to conventional perfect fluid, and its
extra-dimensional part is coupled to a dark pressure through a scalar field. It
is shown that neither early inflation nor current acceleration of the 4D
universe would happen if the non-vacuum states of the scalar field would
contribute to 4D cosmology.Comment: 13 pages, major revision, published online in GR
Maxillary Lesion Presenting As A First Sign Of Multiple Myeloma: Case Report
Plasma cell neoplasia is a lymphoid neoplastic proliferation of B cells. This denomination encloses multiple myeloma (MM), solitary bone plasmacytoma and extramedullary plasmacytoma. MM consists of a clonal proliferation of plasma cells based in the bone marrow, with various degrees of differentiation. Neoplastic cells usually produce great amounts of monoclonal light or heavy chains of immunoglobulin that can be detected in serum or urine. The disease is more frequently in men and the average age at diagnosis is about 60 years. The diagnosis is established by blood and urine exams and medullary biopsy. Patients may present renal failure, bone pain, fatigue, recurrent infections and nervous system dysfunction. Oral manifestations may be the first sign of MM, highlighting the importance of the dentist in the early diagnosis of the disease. Treatment involves mainly irradiation and chemotherapy and the prognosis is generally poor. This paper reports a case of a 65 years old black female who had a complaint of a painful mass in the maxilla that prompted a MM diagnosis. © Medicina Oral.125E344E347Seoane, J., Aguirre-Urizar, J.M., Esparza-Gomez, G., Suarez-Cunqueiro, M., Campos-Trapero, J., Pomareda, M., The spectrum of plasma cell neoplasia in oral pathology (2003) Med Oral, 8, pp. 269-280Lae, M.E., Vencio, E.F., Inwards, C.Y., Unni, K.K., Nascimento, A.G., Myeloma of the jaw bones: A clinicopathologic study of 33 cases (2003) Head Neck, 25, pp. 373-381Ozdemir, R., Kayiran, O., Oruc, M., Karaaslan, O., Kocer, U., Ogun, D., Plasmacytoma of the hard palate (2005) J Craniofac Surg, 16, pp. 164-169Currie, W.J., Hill, R.R., Keshani, D.K., An unusual cause of maxillary tuberosity enlargement (1994) Br Dent J, 177, pp. 60-62Kyle, R.A., Gertz, M.A., Witzig, T.E., Lust, J.A., Lacy, M.Q., Dispenzieri, A., Review of 1027 patients with newly diagnosed multiple myeloma (2003) Mayo Clin Proc, 78, pp. 21-33Gray, S.T., Antunovic, D.M., White, A.E., Non secretory multiple myeloma involving the maxilla: Report of a case with update of biology and new approaches to management (1997) Oral Oncol, 33, pp. 136-140Kyle, R.A., Multiple myeloma: An odyssey of discovery (2000) Br J Haematol, 111, pp. 1035-1044Zachriades, N., Papanicolaou, S., Papavassiliou, D., Vairaktaris, E., Triantafyllou, D., Mezitis, M., Plasma cell myeloma of the jaws (1987) Int J Oral Maxillofac Surg, 16, pp. 510-515Kyle, R.A., Multiple myeloma: Review of 869 cases (1975) Mayo Clin Proc, 50, pp. 29-40Epstein, J.B., Voss, N.J., Stevenson-Moore, P., Maxillofacial manifestations of multiple myeloma. An unusual case and review of the literature (1984) Oral Surg Oral Med Oral Pathol, 57, pp. 267-271Mateo Arias, J., Molina Martinez, M., Borrego, A., Mayorga, F., Amyloidosis of the submaxillary gland (2003) Med Oral, 8, pp. 66-70Reboiras Lopez, M.D., Garcia Garcia, A., Antunez Lopez, J., Blanco Carrion, A., Gandara Vila, P., Gandara Rey, J.M., Anaesthesia of the right lower hemilip as a first manifestation of multiple myeloma. Presentation of a clinical case (2001) Med Oral, 6, pp. 168-172Hsi, E.D., Yegappan, S., Lymphoma Immunophenotyping: A New Era in Paraffin-Section Immunohistochemistry (2001) Advances in Anatomic Pathology, 8, pp. 218-239Bayer-Garner, I.B., Prieto, V.G., Smoller, B.R., Detection of clonality with kappa and lambda immunohistochemical analysis in cutaneous plasmacytomas (2004) Arch Pathol Lab Med, 128, pp. 645-648Shin, J.S., Stopyra, G.A., Warhol, M.J., Multhaupt, H.A.B., Plasmacytoma with aberrant expression of myeloid markers, T-cell markers, and cytokeratin (2001) The Journal of Histochemistry & Cytochemistry, 49, pp. 791-792Rosai, J., (2004) Rosai and Ackerman's Surgical Pathology, pp. 2099-2105. , St Louis: Mosby CoDurie, B.G.M., Stock-Novack, D., Salmon, S.E., Finley, P., Beckord, J., Crowley, J., Prognostic Value of Pretreatment Serum-2 Microglobulin in Myeloma: A Southwest Oncology Group Study (1990) Blood, 75, pp. 823-83
Induced inflation from a 5D purely kinetic scalar field formalism on warped product spaces
Considering a separable and purely kinetic 5D scalar field on a warped
product metric background we propose a new and more general approach for
inducing 4D scalar potentials on a 4D constant foliation of the 5D space-time.
We obtain an induced potential for a true 4D scalar field instead of a
potential for an effective 4D scalar field. In this formalism we can recover
the usual 4D inflationary formalism with a geometrically induced inflationary
potential. In addition the quantum confinement of the inflaton modes is
obtained naturally from the model for at least a class of warping factors.
Besides the 4D inflationary physics that results of this formalism is
independent of the 4D-hypersurface chosen.Comment: 8 pages Accepted for publication in European Physical Journal
Scale invariant scalar metric fluctuations during inflation: non-perturbative formalism from a 5D vacuum
We extend to 5D an approach of a 4D non-perturbative formalism to study
scalar metric fluctuations of a 5D Riemann-flat de Sitter background metric. In
contrast with the results obtained in 4D, the spectrum of cosmological scalar
metric fluctuations during inflation can be scale invariant and the background
inflaton field can take sub-Planckian values.Comment: final version to be published in Eur. Phys. J.
FRW Cosmology From Five Dimensional Vacuum Brans-Dicke Theory
We follow approach of induced matter theory for 5D vacuum BD, introduce
induced matter and potential in 4D hypersurfaces, and employ generalized FRW
type solution. We confine ourselves to scalar field and scale factors be
functions of the time. This makes the induced potential, by its definition,
vanishes. When the scale factor of fifth dimension and scalar field are not
constants, 5D eqs for any geometry admit a power law relation between scalar
field and scale factor of fifth dimension. Hence the procedure exhibits that 5D
vacuum FRW like eqs are equivalent, in general, to corresponding 4D vacuum ones
with the same spatial scale factor but new scalar field and coupling constant.
We show that 5D vacuum FRW like eqs or its equivalent 4D vacuum ones admit
accelerated solutions. For constant scalar field, eqs reduce to usual FRW eqs
with typical radiation dominated universe. For this situation we obtain
dynamics of scale factors for any geometry without any priori assumption. For
nonconstant scalar fields and spatially flat geometries, solutions are found to
be power law and exponential ones. We also employ weak energy condition for
induced matter, that allows negative/positive pressures. All types of solutions
fulfill WEC in different ranges. The power law solutions with negative/positive
pressures admit both decelerating and accelerating ones. Some solutions accept
shrinking extra dimension. By considering nonghost scalar fields and recent
observational measurements, solutions are more restricted. We illustrate that
accelerating power law solutions, which satisfy WEC and have nonghost fields,
are compatible with recent observations in ranges -4/3 < \omega </- -1.3151 and
1.5208 </- n < 1.9583 for dependence of fifth dimension scale factor with usual
scale factor. These ranges also fulfill condition nonghost fields in the
equivalent 4D vacuum BD eqs.Comment: 18 pages, 16 figures, 11 table
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