199680278
Black hole entropy and Hawking radiation spectrum predictions without Immirzi parameter
118611210
Approximation of the naive black hole degeneracy
In 1996, Rovelli suggested a connection between black hole entropy and the area spectrum. Using this formalism and a theorem we prove in this paper, we briefly show the procedure to calculate the quantum corrections to the Bekenstein–Hawking entropy. One can do this by two steps. First, one can calculate the “naive” black hole degeneracy without the projection constraint (in case of the $$U(1)$$ symmetry reduced framework) or the $$SU(2)$$ invariant subspace constraint (in case of the fully $$SU(2)$$ framework). Second, then one can impose the projection constraint or the $$SU(2)$$ invariant subspace constraint, obtaining logarithmic corrections to the Bekenstein–Hawking entropy. In this paper, we focus on the first step and show that we obtain infinite relations between the area spectrum and the naive black hole degeneracy. Promoting the naive black hole degeneracy into its approximation, we obtain the full solution to the infinite relations.
118961549
Black Hole Entropy Prediction without Immirzi Parameter
In our earlier paper "Corrections to the Bekenstein-Hawking entropy and the Hawking radiation spectrum", arXiv:0910.2755, we provided two concrete numerical evidences for the new area spectrum based on the Einstein-Kaufman pseudo tensor as opposed to the Ashtekar variables: namely, the reproduction of the Bekenstein-Hawking entropy without fixing Immirzi parameter and the reproduction of the Hawking radiation spectrum. In this article, we provide another concrete, numerical evidence for this new area spectrum; there was a constant in our earlier article, which was inversely proportional to the density of state, and which we could not fix a priori. Nevertheless, in our earlier article, we obtained this constant to be around 172~173 by fitting it to the Planck radiation spectrum. In this article, we calculate this value using another method. We obtain 172.87...which implies consistency.
118678608
Quantum corrections to the Hawking radiation spectrum
In 1995, Bekenstein and Mukhanov suggested that the Hawking radiation spectrum was discrete if the area spectrum was quantized in such a way that the allowed areas were integer multiples of a single unit area. However, in 1996, Barreira, Carfora, and Rovelli argued that the Hawking radiation spectrum was continuous if the area spectrum was quantized with an infinite number of unit areas, as predicted by loop quantum gravity, rather than quantized with the single unit area considered by Bekenstein and Mukhanov. In this paper, contrary to what Barreira, Carfora, and Rovelli argued, we show that the Hawking radiation spectrum is still discrete when the area spectrum is quantized as loop quantum gravity predicts. In particular, we show that, for a black hole of a given temperature, the Hawking radiation spectrum is truncated at frequencies below a certain frequency.
119237348
Problems with Mannheim’s conformal gravity program
We show that Mannheim's conformal gravity program, whose potential has a term proportional to $1/r$ and another term proportional to $r$, does not reduce to Newtonian gravity at short distances, unless one assumes undesirable singularities of the mass density of the proton. Therefore, despite the claim that it successfully explains galaxy rotation curves, unless one assumes the singularities, it seems to be falsified by numerous Cavendish-type experiments performed at laboratories on Earth whose work have not found any deviations from Newton's theory. Moreover, it can be shown that as long as the total mass of the proton is positive, Mannheim's conformal gravity program leads to negative linear potential, which is problematic from the point of view of fitting galaxy rotation curves, which necessarily requires positive linear potential.
116926585
Third potential evidence for the new area spectrum based on the Einstein-Kaufman pseudo tensor, a conjecture
This paper has been withdrawn by the authors. In our earlier paper "Corrections to the Bekenstein-Hawking entropy and the Hawking radiation spectrum", arXiv:0910.2755, we provided two concrete numerical evidences for the new area spectrum based on the Einstein-Kaufman pseudo tensor as opposed to the Ashtekar variables: namely, the reproduction of the Bekenstein-Hawking entropy without fixing Immirzi parameter and the reproduction of the Hawking radiation spectrum. In this article, we provide another potential, albeit not concrete, numerical evidence for this new area spectrum; there was a constant in our earlier article, which was inversely proportional to the density of state, and which we could not fix a priori. Nevertheless, in our earlier article, we obtained this constant to be around 172$\sim$173 by fitting it to the Planck radiation spectrum. In this article, we propose a mathematical formula that reproduces this value. According to this formula, this constant is around 172.8. Nevertheless, we failed to concretely derive this mathematical formula. Therefore, it is a conjecture.
117761708
Performance of the CREAM calorimeter in accelerator beam test
The CREAM calorimeter, designed to measure the spectra of cosmic-ray nuclei from under 1 TeV to 1000 TeV, is a 20 radiation length (X0) deep sampling calorimeter. The calorimeter is comprised of 20 layers of tungsten interleaved with 20 layers of scintillating fiber ribbons, and is preceded by a pair of graphite interaction targets providing about 0.42 proton interaction lengths (\lambda int). The calorimeter was placed in one of CERN's SPS accelerator beams for calibration and testing. Beams of 150 GeV electrons were used for calibration, and a variety of electron, proton, and nuclear fragment beams were used to test the simulation model of the detector. In this paper we discuss the performance of the calorimeter in the electron beam and compare electron beam data with simulation results.
122691903
Beam test of a dual layer silicon charge detector (SCD) for the CREAM experiment
Abstract The Cosmic Ray Energetics and Mass (CREAM) balloon-borne experiment is designed for direct measurement of high-energy cosmic rays. The experimental goal is to measure single-element fluxes of all cosmic-ray nuclei from hydrogen to iron with energies up to the “knee”, or spectral index change near 10 15 eV , observed in the all-particle spectrum. The dual layer Silicon Charge Detector (SCD) was designed to provide precise charge measurements. Each SCD layer has an active area of 77.9 cm × 79.5 cm and consists of 156 silicon sensors mounted on 24 ladders. Each sensor contains a 4 × 4 array of single-sided DC type silicon pixels with an active area of 2.1 cm 2 . The detector was flown on the second CREAM flight (December 2005–January 2006) and recovered successfully. The SCD was refurbished for the third CREAM flight and tested with high-energy electron and hadron beams at CERN. This paper reports on the performance of the SCD during the beam test.
40972892
Performance of the CREAM-III Calorimeter
Cosmic Ray Energetics And Mass (CREAM) is a balloon-borne experiment to directly measure the elemental spectra of protons to iron nuclei with energies up to ~ 1015 eV. Energies of these cosmic-ray particles are measured by an ionization calorimeter comprised of 20 layers of 1 radiation length thick tungsten plates and 20 layers of 0.5 mm diameter scintillating fibers. Each tungsten plate is 500 times 500 times 3.5 mm3 and the fibers are grouped into fifty 1 cm wide ribbons. After construction, the CREAM-III calorimeter was tested at CERN, the European high energy physics lab, in the H2 beam line of the SPS. Following the CERN test, the calorimeter was integrated into the CREAM-III instrument, and flown successfully in the 3rd flight of the project, during the 2007/8 Antarctic campaign. We present the performance of the CREAM-III calorimeter in lab and beam tests.
118519145
Design and construction of a Cherenkov imager for charge measurement of nuclear cosmic rays
A proximity focusing Cherenkov imager called CHERCAM, has been built for the charge measurement of nuclear cosmic rays with the CREAM instrument. It consists of a silica aerogel radiator plane across from a detector plane equipped with 1,600 1`` diameter photomultipliers. The two planes are separated by a ring expansion gap. The Cherenkov light yield is proportional to the charge squared of the incident particle. The expected relative light collection accuracy is in the few percents range. It leads to an expected single element separation over the range of nuclear charge Z of main interest 1 ? Z26. CHERCAM is designed to fly with the CREAM balloon experiment. The design of the instrument and the implemented technical solutions allowing its safe operation in high altitude conditions (radiations, low pressure, cold) are presented.
119192161
Calibration of the CREAM-I calorimeter
The Cosmic Ray Energetics And Mass (CREAM) calorimeter is designed to measure the spectra of cosmic-ray particles over the energy range from ~10 11 eV to ~10 15 eV. Its first flight as part of the CREAM-I balloon-borne payload in Antarctica during the 2004/05 season resulted in a record- breaking 42 days of exposure. Calorimeter calibration using various beam test data will be discussed in an attempt to assess the uncertainties of the energy measurements.