2,102 research outputs found
WALS estimation and forecasting in factor-based dynamic models with an application to Armenia
Two model averaging approaches are used and compared in estimating and forecasting dynamic factor models, the well-known BMA and the recently developed WALS. Both methods propose to combine frequentist estimators using Bayesian weights. We apply our framework to the Armenian economy using quarterly data from 2000ā2010, and we estimate and forecast real GDP and inflation dynamics.Dynamic models;Factor analysis;Model averaging;Monte Carlo;Armenia
Structural versus Matching Estimation: Transmission Mechanisms in Armenia
Opting for structural or reduced form estimation is often hard to justify if one wants to both learn about the structure of the economy and obtain accurate predictions. In this paper, we show that using both structural and reduced form estimates simultaneously can lead to more accurate policy predictions. Our findings are based on using new information criteria whose econometric properties allow us to pick for both methods the impulse responses that are valid and relevant for prediction. We illustrate our findings in the context of analyzing the monetary transmission mechanism for Armenia. Based on picking valid and relevant information from both structural and reduced form matching estimation, our findings suggest that the interest rate targeting and the exchange rate channel are well specified and strongly reinforce each other in promoting the recent double-digit growth Armenia experienced before the crisis.Armenia;monetary policy;structural model;GMM and MDE estimation;information criteria;valid and relevant IRFs
Measurement of , K, p transverse momentum spectra with ALICE in proton-proton collisions at 0.9 and 7 TeV
Results of the measurement of the , K, p transverse momentum
() spectra at mid-rapidity in proton-proton collisions at
TeV are presented. Particle identification was performed using
the energy loss signal in the Inner Tracking System (ITS) and the Time
Projection Chamber (TPC), while information from the Time-of-Flight (TOF)
detector was used to identify particles at higher transverse momentum. From the
spectra at TeV the mean transverse momentum ()
and particle ratios were extracted and compared to results obtained for
collisions at TeV and lower energies.Comment: Quark Matter 2011 proceeding
Diffraction dissociation in proton-proton collisions at = 0.9 TeV, 2.76 TeV and 7 TeV with ALICE at the LHC
The relative rates of single- and double- diffractive processes were measured
with the ALICE detector by studying properties of gaps in the pseudorapidity
distribution of particles produced in proton-proton collisions at =
0.9 TeV, 2.76 TeV and 7 TeV. ALICE triggering efficiencies are determined for
various classes of events, using a detector simulation validated with data on
inclusive particle production. Cross-sections are determined using van der Meer
scans to measure beam properties and obtain a measurement of the luminosity
The influence of quark matter at high densities on binary neutron star mergers
We consider the influence of potential quark matter existing at high densities in neutron star (NS) interiors on gravitational waves (GWs) emitted in a binary NS merger event. Two types of equations of state (EoSs) at zero temperature are used - one describing pure nuclear matter and the other nuclear matter with a phase transition to quark matter at very high densities. Binary equilibrium sequences close to the innermost stable circular orbit (ISCO) are calculated to determine the GW frequencies just before the merger. It is found that the effects of the EoSs begin to play a role when gravitational masses are larger than Māā 1.5 Mā. The difference in the GW frequency at the ISCO increases by up to ā10 per cent for the maximum mass permitted by the EoSs. We then perform three-dimensional hydrodynamic simulations for each EoS while varying the initial mass and determine the characteristic GW frequencies of the merger remnant. The implications of the presence of quark matter show up mainly in the collapse behaviour of the merger remnant. If the collapse does not take place immediately after the merger, we find a phase difference between the two EoSs in the post-merger GW signal. We also compare the GW frequencies emitted by the remnant of the merger to values obtained from simulations using a polytropic EoS and find an imprint of the non-constant adiabatic index of our EoSs. All calculations are based on the conformally flat approximation to general relativity and the GW signal from the merger simulation is extracted up to quadrupole orde
The Influence of Quark Matter at High Densities on Binary Neutron Star Mergers
We consider the influence of potential quark matter existing at high
densities in neutron star interiors on gravitational waves (GW) emitted in a
binary neutron star merger event. Two types of equations of state (EoS) at zero
temperatures are used, one describing pure nuclear matter, the other nuclear
matter with a phase transition to quark matter at very high densities. Binary
equilibrium sequences close to the innermost stable circular orbit (ISCO) are
calculated to determine the GW frequencies just before merger. It is found that
EoS effects begin to play a role for gravitational masses larger than
. The difference in the gravitational wave frequency
at the ISCO grows to up to for the maximal allowed mass given by
the EoSs used. Then, we perform 3D hydrodynamic simulations for each EoS
varying the initial mass and determine the characteristic GW frequencies of the
merger remnants. The implications of quark matter show up mainly in a different
collapse behaviour of the merger remnant. If the collapse does not take place
immediately after merger, we find a phase difference between two EoS's in the
post-merger GW signal. We also compare the GW frequencies emitted by the merger
remnant to values from simulations using a polytropic EoS and find an imprint
of the non-constant adiabatic index of our EoSs. All calculations are based on
the conformally flat (CF) approximation to general relativity and the GW signal
from the merger simulation is extracted up to quadrupole order.Comment: 13 pages, 8 figure
Modelling and Forecasting Domestic Tourism. Case Study from Armenia
This paper summarizes the arguments and counterarguments within the scientific discussion on the issue of modelling and forecasting domestic tourism. During Covid-19 many countries tried to develop domestic tourism as an alternative to inbound tourism. In Armenia domestic tourism has grown recently, and in 2020 the decrease was 33% compared to last year. The main purpose of the research is to model and forecast domestic tourism growth in Armenia
Quark Matter in Neutron Star Mergers
Binary neutron star mergers are expected to be one of the most promising
source of gravitational waves (GW) for the network of laser interferometric and
bar detectors becoming operational in the next few years. The merger wave
signal is expected to be sensitive to the interior structure of the neutron
star (NS). The structure of high density phases of matter is under current
experimental investigation in heavy-ion collisions. We investigate the
dependence of the merger process and its GW signal on the presence of quarks in
these phases by performing numerical simulations, where the smoothed particle
hydrodynamics (SPH) method and the conformally flat approximation for the
3-geometry in general relativistic gravity are implemented.Comment: 4 Pages, 4 Figures, Proc. Nuclei in the Cosmos 7, 200
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