DERIVATION OF WEINBERG’S RELATION IN AN INFLATIONARY UNIVERSE
IOANNIS IRAKLIS HARANAS
Department of Physics and Astronomy
E-mail:
ioannis@yorku.ca
Abstract. We propose a
derivation of the empirical Weinberg
relation for the
mass of an elementary particle in an inflationary-type
universe. Our derivation
produces the well-known standard Weinberg relation for the mass of an
elementary particle, along with an
extra-term that depends on the inflationary
potential, as well as Hubble’s constant. This derivation is based on
Zeldovich’s result for
the cosmological constant L, in the context of quantum field theory. The extra-term
can be
understood as a small correction to the
mass of the elementary particle due to
inflation. This term also enables us to obtain an expresion for the
initial
value of the field fO
and for two different kinds of inflationary potentials chosen. For
this value of the field fO, Weinberg’s relation
can be possible in its
original form. Closed, flat,
and open universes give the mass of an elementary particle close to
that of a
pion, or 140 MeV/c2.
Key words: inflationary cosmology – quantum theory of field –cosmological constant.
PHOTOMETRIC STUDY OF THE ECLIPSING BINARY VW LEONIS MINORIS
ALEXANDRU DUMITRESCU
Astronomical
Institute of the
Str.
Cuţitul de Argint 5,
RO-752121
E-mail:
alex@aira.astro.ro
Abstract. VW LMi (HIP
54003) was discovered by HIPPARCOS/TYCHO as
a
of this star. A photometric solution is derived with the Djurasevic
model. The binary, having the temperatures of the components
approximately
equal, is an overcontact system. Phase shifts of the light curve maxima
were
observed.
Key words: astrophysics – stars – eclipsing binaries – VW LMi – photometric solutions.
HIGH-SPEED PLASMA STREAMS ANALYSIS DURING THE SOLAR POLAR FIELD REVERSALS
GEORGETA MARIŞ1, OVIDIU MARIŞ2,3,4
1Astronomical
Institute of the
Str.
Cuţitul de Argint 5,
RO-040558
gmaris@aira.astro.ro
2Institute for Space Sciences
P.O.Box
MG-23, RO-77125
maris@venus.nipne.ro
3Research
Associate at: Astronomical Institute of the
4Research Associate at: Istituto Nazionale di Fisica Nucleare, Sezione di Perugia
Via
A.
Pascoli, 06123 Perugia, Italy
Ovidiu.Maris@pg.infn.it
Abstract. The behavior of
the high-speed plasma streams (HSPSs) in
the solar
wind is investigated during the period of the solar
cycles (SCs) Nos. 20–22
(1964–1996) and the intervals of the solar polar field reversal. The
analysis
is performed taking into account
the following parameters: the durations (in days); the
maximum
velocities; the velocity gradients; the importance of the
streams. The
time variation of the high-speed plasma stream parameters and
their occurrence rate shows an 11-year periodicity with some
differences
between the considered SCs. The increased activity of high-speed plasma
streams
on the descendant phases of the cycles, regardless of
their solar source,
proves the existence of some special local conditions for the solar
plasma and
the magnetic field on a large scale that
allow the ejection of high velocity
plasma streams. This fact led us to analyse the high-speed plasma
stream
parameters during the solar
magnetic field reversal intervals. The significant
increase of the flare-generated high-speed plasma stream (FG_HSPS)
parameters
during
a reversal interval can be explained considering their “blob” structure
and the topology of the poloidal magnetic field during this interval.
Then, any
shield of the solar poloidal field lines is absent and the stream will
not lose
its energy in any reconnection. Besides this, the quadrupole
or even octupole
structure of the large-scale solar field could bring small-scale
magnetic field
topologies (in active regions) that allow the
gathering of greater energies as
well as stronger accelerations in a solar eruption. The decrease of the
mean
values of the coronal hole generated
high-speed plasma stream (CH_HSPS)
parameters in reversal intervals could be determined by some relaxation
of the
CH magnetic field due to
the absence of the general magnetic field lines which
would result in less efficient particle acceleration.
Key words: solar wind – high-speed plasma streams – 11-year solar cycle - solar polar field reversal.
SOLAR CYCLE 23: FORECASTS AND OBSERVATIONS
GEORGETA MARIŞ1, MIRUNA DANIELA POPESCU1, 2, DIANA BEŞLIU1
1
Astronomical Institute of the
Str.
Cuţitul de
Argint 5, RO-040558 1 Bucharest, Romania
E-mails:
gmaris@aira.astro.ro; deanna@aira.astro.ro
2
E-mail:
mdp@star.arm.ac.uk
Abstract. We shortly
analyse the solar cycle (SC) 23 behaviour
during May
1996-July 2003, making also a
comparison
with
the previous three cycles. Some aspects concerning the forecasts of its
maximum are presented. In accordance to some early
predictions for the
following cycle, our empirical method, based on observing the flare
energy
release during the descendant
phase of the precedent SC, estimate that the
amplitude of SC 24 will be low. Furthermore, it
is likely
that the Sun may be heading
towards a “Maunder” type of minimum, continuing a
rapid decline, which started with SC 23.
Key words: Solar 11-year cycles - solar cycle 23 - forecast methods.
SPHEROIDAL
AND TOROIDAL MODES FOR
TIDAL KINETIC ENERGY
IN AXISYMMETRIC,
SLIGHTLY ELLIPTICAL,
ELASTIC BODIES
JUAN GETINO
1, ALBERTO
ESCAPA 2, AMELIA GARCÍA 3
1
Grupo de Mecanica Celeste
Facultad
de
Ciencias, Universidad de Valladolid, 47005 Valladolid, Spain
E-mail:
getino@maf.uva.es
2
Grupo de Mecanica Celeste
Departamento
de Matemática Aplicada, Universidad de Alicante, apdo. 99
03080
Alicante, Spain
E-mail:
Alberto.Escapa@ua.es
3
Grupo de Mecanica Celeste
Departamento
de Matemática Aplicada a la Ingeniería
E.T.S.I.I.,
Paseo del Cauce s/n, 47011 Valladolid, Spain
E-mail:
amegar@wmatem.eis.uva.es
Abstract. This paper is an
extension of the previous one by
Getino et
al.(2002), where we studied the increase of the kinetic energy of
spherical
elastic bodies due to the tidal perturbation, taking into account the
spheroidal and toroidal modes of the displacement vector.
In this paper we
consider axisymmetrical, slightly elliptical bodies, whose density and
rheological parameters are expressed as a sum of
a term with radial dependence,
corresponding to a spherical body, and terms that depend on the radius and on the latitude. By using the
well-known properties of the Legendre polynomials, we prove that for
the
spheroidal modes, the only terms of the expansion of the
perturbing potential
that intervene in the kinetic energy correspond to n =
0, 2, 4, while for the toroidal modes we have the contributions
of n = 1, 3. The corresponding tensor
of inertia of each of these terms is obtained as a function of some
integrals
in r whose numerical
values depend on
the internal structure of the body. The result thus obtained are the
general
one, and is valid for any elastic body in the
linear theory of the elasticity
under the above-mentioned symmetrical properties.
Key words: celestial mechanics – tides – elastic bodies – Earth’s rotation.
LIBRATION POINTS IN MANEV’S CIRCULAR RESTRICTED THREE-BODY PROBLEM
RODICA ROMAN 1, VASILE MIOC 2
1
Astronomical Institute of the
Astronomical
Observatory Cluj-Napoca
Str.
Cireşilor
19, RO-3400 Cluj-Napoca, Romania
E-mail:
rroman@math.ubbcluj.ro
2
Astronomical Institute of the
Str.
Cuţitul de
Argint 5, RO-752121 Bucharest, Romania
E-mail:
vmioc@aira.astro.ro
Abstract. We tackle the
circular restricted three-body problem
within the
framework of Manev’s classical post-Newtonian field,
associated to a potential
of the form A/r + B/r2. We establish the
equations of motion and prove the existence of an analog of the
Jacobian first
integral. After emphasizing some features of the zero-relative-velocity
surfaces, we approach the main topic: libration
points. As in the Newtonian
case, there are three collinear libration points, and, if they exist,
two
triangular libration points (situated
in the orbital plane of the primaries).
We give the positions of all these points. If triangular points exist,
they may
not form equilateral
triangles; the triangles are isosceles (always possible
situation) for equal masses of the primaries, and scalene else.
Key words: celestial mechanics – restricted three-body problem – libration points – post-Newtonian fields – Manev’s field.
THE
photogravitational model
MIRA-CRISTIANA
ANISIU
T.
Popoviciu
Institute of Numerical Analysis
Str.
Republicii 37, R0-3400 Cluj-Napoca, Romania
E-mail:
mira@math.ubbcluj.ro
Abstract. The
photogravitational model of Constantin Popovici
combines the
Newtonian attracting force with a radiative repelling one.
We consider a
post-Newtonian attracting force, namely the one generated by a
Manev-type
potential, and the same repelling force
defined by Popovici. We prove that for
this new problem the integration of the motion equations can be
performed in a
similar way
as in Popovici’s model. The study of the equilibria reveals
specific situations for the Popovici-Manev model, as the existence of
saddles.
Key words: photogravitational models – equilibria.
SYMMETRIES IN THE ISOSCELES THREE-BODY PROBLEM
VASILE MIOC 1, DORINA STANCU 1, 2
1
Astronomical Institute of the
Str.
Cuţitul de Argint 5,
RO-752121
E-mail: vmioc@aira.astro.ro
2 Institute of Space Sciences, Gravitational Research Laboratory
P.O.
Box MG-6, RO-76900
E-mail: doramatro@yahoo.com
Abstract. We tackle the
spatial three-body problem from a single
standpoint:
symmetries. The vector field that features the
general problem presents nice
symmetries that form a sixteen-element Abelian group endowed with an
idempotent
structure.
The reduced isosceles problem (obtained by fixing the angular
momentum constant), which includes the celebrated circular
and elliptic
Sitnikov problems, exhibits a four-element group of symmetries with the
same
properties.
Key words: celestial mechanics – isosceles three-body problem – symmetries.
THE
VERTICAL DEVIATION DETERMINATION BY
AN ASTRONOMICAL GEODETIC
METHOD
(I): PRESENT CONTEXT
OCTAVIAN
BĂDESCU 1,2,
PETRE POPESCU 2, RADU
POPESCU 2
1 Technical University of Civil Engineering
Bd.
Lacul Tei 124,
E-mail:
octavian@aira.astro.ro
2,
Astronomical
Institute of the
Str.
Cuţitul de
Argint 5, RO-040558 Bucharest, Romania
E-mail:
petre@aira.astro.ro, pradu@aira.astro.ro
Abstract. This paper
represents the first of a series in which we
intend to
describe and use an astronomical geodetic method for the
determination of
vertical deviation. We shall present some reasons for developing the
method. We
emphasize the advantage of vertical
deviation determination by astronomical and
geodetic measurements in the present context of GPS technology and
electronic
devices
for high-accuracy angular measurements.
Key words: astrometry – geodesy – vertical deviation.