92 research outputs found
Conceptual unification of elementary particles, black holes, quantum de Sitter and Anti de Sitter string states
We provide a conceptual unified description of the quantum properties of
black holes (BH), elementary particles, de Sitter (dS) and Anti de Sitter (AdS)
string states.The conducting line of argument is the classical-quantum (de
Broglie, Compton) duality here extended to the quantum gravity (string) regime
(wave-particle-string duality). The semiclassical (QFT) and quantum (string)
gravity regimes are respectively characterized and related: sizes, masses,
accelerations and temperatures. The Hawking temperature, elementary particle
and string temperatures are shown to be the same concept in different energy
regimes and turn out the precise classical-quantum duals of each other;
similarly, this result holds for the BH decay rate, heavy particle and string
decay rates; BH evaporation ends as quantum string decay into pure (non mixed)
radiation. Microscopic density of states and entropies in the two
(semiclassical and quantum) gravity regimes are derived and related, an
unifying formula for BH, dS and AdS states is provided in the two regimes. A
string phase transition towards the dS string temperature (which is shown to be
the precise quantum dual of the semiclassical (Hawking-Gibbons) dS temperature)
is found and characterized; such phase transition does not occurs in AdS alone.
High string masses (temperatures) show a further (square root temperature
behaviour) sector in AdS. From the string mass spectrum and string density of
states in curved backgrounds, quantum properties of the backgrounds themselves
are extracted and the quantum mass spectrum of BH, dS and AdS radii obtained.Comment: New original material; one minor misprint in eq.(1.3) correcte
Advances in String Theory in Curved Space Times
String Quantum Gravity is motivated and introduced. Advances in the study of
the classical and quantum string dynamics in curved spacetime are reported:
1-New Classes of Exact Multistring solutions in curved spacetimes. 2-Mass
spectrum of Strings in Curved Spacetimes. 3-The effect of a Cosmological
Constant and of Spacial Curvature on Classical and Quantum Strings. 4-Classical
splitting of Fundamental Strings. 5-The General String Evolution in constant
Curvature Spacetimes. 6-The Conformal Invariance Effects.Comment: Chalonge School Lectures on Astrofundamental Physics, 9th Course 7-18
September 2002, To appear in the Proceedings, NATO ASI Series edited by N.G.
Sanchez and Yu. Parijskij, Kluwer Pu
Classical and Quantum Strings in plane waves, shock waves and spacetime singularities: synthesis and new results
Key issues of classical and quantum strings in gravitational plane waves,
shock waves and spacetime singularities are synthetically understood. This
includes the string mass and mode number excitations, energy-momentum tensor,
scattering amplitudes, vaccum polarization and wave-string polarization effect.
The role of the real pole singularities characteristic of the tree level string
spectrum (real mass resonances) and that of spacetime singularities is clearly
exhibited. This throws light on the issue of singularities in string theory
which can be thus classified and fully physically characterized in two
different sets: strong singularities (poles of order equal or larger than 2,
and black holes), where the string motion is collective and non oscillating in
time, outgoing and scattering states do not appear, the string does not cross
the singularities, and weak singularities (poles of order smaller than 2, Dirac
delta, and conic/orbifold singularities) where the whole string motion is
oscillatory in time, outgoing and scattering states exist, and the string
crosses the singularities. Commom features of strings in singular plane
backgrounds and in inflationary backgrounds are explicitly exhibited. The
string dynamics and the scattering/excitation through the singularities
(whatever their kind: strong or weak) is fully physically consistent and
meaningful.Comment: Synthesis and new material. 18 pages, no figure
Quantum Discrete Levels of the Universe from the Early Trans-Planckian Vacuum to the Late Dark Energy
The standard model of the universe is further completed back in time before
inflation in agreement with observations, classical-quantum gravity duality and
quantum space-time. Quantum vacuum energy bends the space-time and produces a
constant curvature de Sitter background. We link de Sitter universe and the
cosmological constant to the (classical and quantum) harmonic oscillator.
Quantum discrete cosmological levels are found: size, time, vacuum energy,
Hubble constant and gravitational (Gibbons-Hawking) entropy from the very early
trans-planckian vacuum to the classical today vacuum energy. For each level , the two: post and pre (trans)-planckian phases are covered: In
the post-planckian universe, the levels (in planck units) are: Hubble constant
, vacuum energy ,
entropy . As increases, radius, mass and increase,
and decrease and {\it consistently} the universe {\it
classicalizes}. In the pre-planckian (trans-planckian) phase, the quantum
levels are: , denoting quantum. The -levels cover {\it all} scales from
the far past highest excited trans-planckian level with finite
curvature, and minimum entropy ,
decreases till the planck level and enters the post-planckian phase
e.g: with the most
classical value , ,
. We implement the Snyder-Yang algebra in this context
yielding a consistent group-theory realization of quantum discrete de Sitter
space-time, classical-quantum gravity duality symmetry and a clarifying
unifying picture.(Abridged)Comment: Published version in Phys Rev D, 54 pages, 1 figure, new material.
arXiv admin note: text overlap with arXiv:1912.0665
Warm Dark Matter Galaxies with Central Supermassive Black-Holes
We generalize the Thomas-Fermi approach to galaxy structure to include
self-consistently and non-linearly central supermassive black holes. This
approach naturally incorporates the quantum pressure of the warm dark matter
(WDM) particles and shows its full powerful and clearness in the presence of
supermassive black holes (SPMHs). We find the main galaxy and central black
hole magnitudes: halo radius r_h , halo mass M_h, black hole mass M_BH,
velocity dispersion, phase space density, with their realistic astrophysical
values, masses and sizes over a wide galaxy range. The SMBH masses arise
naturally in this framework. Our extensive numerical calculations and detailed
analytic resolution show that with SMBH's, both WDM regimes: classical
(Boltzmann dilute) and quantum (compact) do necessarily co-exist in any galaxy:
from the smaller and compact galaxies to the largest ones. The transition from
the quantum to the classical region occurs precisely at the same point r_A
where the chemical potential vanishes. A novel halo structure with three
regions shows up: A small quantum compact core of radius r_A around the SMBH,
followed by a less compact region till the BH influence radius r_i, and then
for r> r_i the known halo galaxy shows up with its astrophysical size. Three
representative families of galaxy plus central SMBH solutions are found and
analyzed:small, medium and large galaxies having SMBH masses of 10^5, 10^7 and
10^9 M_sun respectively. A minimum galaxy size and mass ~ 10^7 M_sun larger
than the one without SMBH is found. Small galaxies in the range 10^4 M_sun <
M_h < 10^7 M_sun cannot harbor central SMBHs. We find novel scaling M_BH - r_h
- M_h relations. The galaxy equation of state is derived: The pressure P(r)
takes huge values in the SMBH vecinity and then sharply decreases entering the
classical region following a local perfect gas behaviour.(Abridged)Comment: 31 pages, 14 figures, new materia
New Developments in String Gravity and String Cosmology.A Summary Report
New Developments in String Gravity and String Cosmology are reported:
1-String driven cosmology and its Predictions. 2-The primordial gravitational
wave background in string cosmology. 3-Non-singular string cosmologies from
Exact Conformal Field Theories. 4-Quantum Field Theory, String Temperature and
the String Phase of de Sitter space-time, 5-Hawking Radiation in String Theory
and the String Phase of Black Holes. 6-New Dual Relation between Quantum Field
Theory regimes and String regimes in Curved Backgrounds, and the 'QFT/String
Tango'. 7- New Coherent String States and Minimal Uncertainty Principle in WZWN
modelsComment: Chalonge School Lectures on Astrofundamental Physics, 9th Course 7-18
September 2002, To appear in the Proceedings edited by N.G. Sanchez and Yu.
Parijskij, NATO ASI Series, Kluwer Pu
Coherent states of quantum spacetimes for black holes and de Sitter spacetime
We provide a group theory approach to coherent states describing quantum space-time and its properties. This provides a relativistic framework for the metric of a Riemmanian space with bosonic and fermionic coordinates, its continuum and discrete states, and a kind of "quantum optics"for the space-time. New results of this paper are: (i) The space-time is described as a physical coherent state of the complete covering of the SL(2C) group, e.g., the metaplectic group Mp(n). (ii) (The discrete structure arises from its two irreducible even (2n) and odd (2n+1) representations, (n=1,2,3...), spanning the complete Hilbert space H=Hodd Heven. Such a global or complete covering guarantees the CPT symmetry and unitarity. Large n yields the classical and continuum manifold, as it must be. (iii) The coherent and squeezed states and Wigner functions of quantum-space-time for black holes and de Sitter, and (iv) for the quantum space-imaginary time (instantons), black holes in particular. They encompass the semiclassical space-time behavior plus high quantum phase oscillations, and notably account for the classical-quantum gravity duality and trans-Planckian domain. The Planck scale consistently corresponds to the coherent state eigenvalue α=0 (and to the n=0 level in the discrete representation). It is remarkable the power of coherent states in describing both continuum and discrete space-time. The quantum space-time description is regular, there is no any space-time singularity here, as it must be.Fil: Cirilo, Diego Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física del Plasma. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física del Plasma; ArgentinaFil: Sanchez, Norma G.. Sorbonne University; Franci
Self-Gravitating Phase Transitions: Point Particles, Black Holes and Strings
We compute the quantum string entropy S_s(m,j) of the microscopic string
states of mass m and spin j in two physically relevant backgrounds: Kerr
(rotating) black holes and de Sitter (dS) space-time. We find a new formula for
the quantum gravitational entropy S_{sem} (M, J), as a function of the usual
Bekenstein-Hawking entropy S_{sem}^(0)(M, J). We compute the quantum string
emission by a black hole in de Sitter space-time (bhdS). In all these cases:
(i) strings with the highest spin, and (ii) in dS space-time, (iii) quantum
rotating black holes, (iv) quantum dS regime, (v) late bhdS evaporation, we
find a new gravitational phase transition with a common distinctive universal
feature: A square root branch point singularity in any space-time dimensions.
This is the same behavior as for the thermal self-gravitating gas of point
particles (de Vega-Sanchez transition), thus describing a new universality
class.Comment: Invited lecture at `Statistical Mechanics of Non-Extensive Systems',
Observatoire de Paris, 24-25 October 2005, to be published in a Special issue
of `Les Comptes rendus de l'Academie des sciences', Elsevie
Initial stage of atherosclerosis in aorta of rabbits by administering cholesterol
Para obtener un modelo experimental de ateroesclerosis aórtica, se suministraron tres dosis de colesterol dietético (0,62; 0,93 y 1,24 g/día) durante 60 días a conejos neozelandeses machos adultos. Se evaluaron los niveles séricos de colesterol, colesterol-HDL y LDL, aspartato aminotransferasa (AST) y alanin aminotransferasa (ALT), así como el desarrollo de ateroesclerosis en aorta. El incremento en la dosis de 0,62 a 0,93 g/día de colesterol ocasionó un aumento significativo (p≤0,05) en la colesterolemia (de 6,79 ±2,34 a 9,51 ±0,10 g/l), principalmente por incremento del colesterol-LDL. La dosis de 1,24 g/día no indujo aumento adicional de la colesterolemia comparado con la dosis de 0,93 g/ día. La colesterolemia fue muy variable entre los conejos que recibieron 0,62 g/día; las dosis mayores de colesterol redujeron esta variabilidad. Las actividades ALT y AST permanecieron normales hasta el día 30 de la experiencia, incrementándose significativamente en el día 60 (p≤0,05) en los grupos que recibieron 0,93 y 1,24 g/día, asociadas a degeneración grasa hepática. Las tres dosis de colesterol indujeron áreas sudanofílicas de extensión variable en aorta. Las lesiones en aorta se caracterizaron por un incremento focal del espesor intimal causado por la infiltración de macrófagos espumosos y músculo liso, entremezclados en proporción variable con depósitos de matriz extracelular. En conclusión, se confirma la sensibilidad del conejo neozelandés a desarrollar hipercolesterolemia y lesiones ateroescleróticas en un corto período de tiempo con una dieta rica en colesterol. La dosis de 0,93 g/día durante 60 días fue la que indujo una respuesta hipercolesterolémica con menor variabilidad entre los conejos y lesiones ateroescleróticas bien desarrolladas. El modelo experimental de ateroesclerosis temprana permitirá estudiar el efecto ateroprotector de diferentes medicamentos y alimentos funcionales.To obtain an experimental model of aortic atherosclerosis, male adult New Zealand rabbits were fed with three doses of dietary cholesterol (0.62, 0.93 and 1.24 g/day) for 60 days. Serum cholesterol, HDL and LDL-cholesterol, aspartate aminotransferase (AST), alanin aminotransferase (ALT) and the development of atherosclerosis in aorta, were evaluated. Increased dietary cholesterol from 0.62 to 0.93 g/day resulted in a significant increase (p≤0.05) in serum cholesterol (from 6.79 ±2.34 to 9.51 ±0.10 g/l), due mainly to the increase in LDL-cholesterol. The dose of 1.24 g/day did not induce further increase in cholesterolemia compared to the dose of 0.93 g/day. Serum cholesterol was highly variable among rabbits that received 0.62 g/day, this variability was reduced with the highest dose of cholesterol. ALT and AST activities remained normal until day 30 of experience, increasing significantly at day 60 (p≤0.05) in the groups receiving cholesterol at the doses of 0.93 and 1.24 g/day, associated with liver fatty degeneration. All doses of cholesterol induced aortic sudanophilic lesion areas of variable surface. Aortic lesions were characterized by a focal increase in intima thickening caused by infiltration of foamy macrophages and smooth muscle mixed in variable proportions with extracellular matrix deposition. In conclusion, the sensitivity of the New Zealand rabbit to develop hypercholesterolemia and atherosclerotic lesions in a short period of time when consuming a high cholesterol diet, is confirmed. The dose of 0.93 g/day for 60 days caused a lower variability in the hypercholesterolemic response among rabbits with significant development of atherosclerotic lesions. This model of early atherosclerosis will allow the study of the atheroprotective effects of different medicines and functional foods.Fil: Lértora, W. J.. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias; ArgentinaFil: Billordo, G. I.. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias; ArgentinaFil: Mussart, Norma Beatriz. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Catugno, M. S.. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias; ArgentinaFil: Sanchez Negrette, M.. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias; Argentin
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