2,717 research outputs found
Spectra, vacua and the unitarity of Lovelock gravity in D-dimensional AdS spacetimes
We explicitly confirm the expectation that generic Lovelock gravity in D
dimensions has a unitary massless spin-2 excitation around any one of its
constant curvature vacua just like the cosmological Einstein gravity. The
propagator of the theory reduces to that of Einstein's gravity, but scattering
amplitudes must be computed with an effective Newton's constant which we
provide. Tree-level unitarity imposes a single constraint on the parameters of
the theory yielding a wide range of unitary region. As an example, we
explicitly work out the details of the cubic Lovelock theory.Comment: 9 pages, 2 references adde
Unitarity analysis of general Born-Infeld gravity theories
We develop techniques of analyzing the unitarity of general Born-Infeld (BI)
gravity actions in D-dimensional spacetimes. Determinantal form of the action
allows us to find a compact expression quadratic in the metric fluctuations
around constant curvature backgrounds. This is highly nontrivial since for the
BI actions, in principle, infinitely many terms in the curvature expansion
should contribute to the quadratic action in the metric fluctuations around
constant curvature backgrounds, which would render the unitarity analysis
intractable. Moreover in even dimensions, unitarity of the theory depends only
on finite number of terms built from the powers of the curvature tensor. We
apply our techniques to some four-dimensional examples.Comment: 26 pages, typos corrected, version to appear in Phys. Rev.
Drying kinetic and physical properties of green laird lentil (Lens culinaris) in microwave drying
The objective of this study was to study the drying kinetics of green laird lentil (Lens culinaris) in microwave drying method. The drying data were fitted to the various thin-layer models. All the models were compared using three statistical parameters, that is, coefficient of determination R2, reduced mean square of the deviation X2 and root means square error RMSE. Also, the lentil’s physical and mechanical features crude protein, oil and ash parameters were specified under different microwave levels. It was concluded according to these values that the recommended model is the best model, which can define the drying curves at the practices at 300, 400, 550, 700 and 800 W in drying lentil by microwave.Key words: Microwave, lentil, physical properties, crude protein, drying
Outbreak of Phytophthora cinnamomi causing severe decline of avocado trees in southern Turkey
Acknowledgements: This research was supported by Bati Akdeniz Agricultural Research Institute (BATEM), and we appreciate the help of the staff of the Ministry of Agriculture and Forestry. We are also thankful to Dr Emrah Yıldırım for preparation of the map.Peer reviewedPostprin
Energy in Topologically Massive Gravity
We define conserved gravitational charges in -cosmologically extended-
topologically massive gravity, exhibit them in surface integral form about
their de-Sitter or flat vacua and verify their correctness in terms of two
basic types of solution.Comment: 6 page
Conserved Charges of Higher D Kerr-AdS Spacetimes
We compute the energy and angular momenta of recent D-dimensional Kerr-AdS
solutions to cosmological Einstein gravity, as well as of the BTZ metric, using
our invariant charge definitions.Comment: 11 pages, references added, equation correcte
The chicken or the egg; or Who ordered the chiral phase transition?
We draw an analogy between the deconfining transition in the 2+1 dimensional
Georgi-Glashow model and the chiral phase transition in 3+1 dimensional QCD.
Based on the detailed analysis of the former (hep-th/0010201) we suggest that
the chiral symmetry restoration in QCD at high temperature is driven by the
thermal ensemble of baryons and anti-baryons. The chiral symmetry is restored
when roughly half of the volume is occupied by the baryons. Surprisingly
enough, even though baryons are rather heavy, a crude estimate for the critical
temperature gives Mev. In this scenario the binding of the instantons
is not the cause but rather a consequence of the chiral symmetry restoration.Comment: 22 pages, 7 figures, comments about chiral symmetry at finite nuclear
density are adde
COVID-19 vaccine-related attitudes and concerns of chemotherapy patients
Objective: This study aimed to examine the attitudes and concerns of chemotherapy patients related to COVID-19 vaccination and determine factors associated with their vaccine behavior.
Patients and Methods: A cross-sectional, descriptive study was conducted with 300 patients who received chemotherapy in the oncology outpatient clinic of a University Hospital in Istanbul in October 2021. Based on our power calculation, a minimum sample size of 264 patients was needed. However, we recruited a sample of 300 to increase the power of the study. Data were collected online using a patient information form and the Attitudes Towards the COVID-19 Vaccine Scale. The data were analyzed using descriptive statistics and parametric tests.
Results: The participants had a mean age of 55.64±13.80 years, 56.7% were women, 64% were married, 38.3% were high school graduates, and 35.7% were homemakers. Age, education level, and chronic disease were associated only with negative attitudes towards the COVID-19 vaccine; gender was associated with positive attitudes. Being vaccinated against COVID-19 was associated with 99% lower negative attitudes and 66.9 times higher positive attitudes towards the COVID-19 vaccine, while men had 76% lower positive attitudes than women.
Conclusions: Overall, patients receiving chemotherapy had a favorable attitude toward and high acceptance of the COVID-19 vaccine
Yang-Mills Solutions on Euclidean Schwarzschild Space
We show that the apparently periodic Charap-Duff Yang-Mills `instantons' in
time-compactified Euclidean Schwarzschild space are actually time independent.
For these solutions, the Yang-Mills potential is constant along the time
direction (no barrier) and therefore, there is no tunneling. We also
demonstrate that the solutions found to date are three dimensional monopoles
and dyons. We conjecture that there are no time-dependent solutions in the
Euclidean Schwarzschild background.Comment: 12 pages, references added, version to appear in PR
Calorons in Weyl Gauge
We demonstrate by explicit construction that while the untwisted
Harrington-Shepard caloron is manifestly periodic in Euclidean time,
with period , when transformed to the Weyl () gauge,
the caloron gauge field is periodic only up to a large gauge
transformation, with winding number equal to the caloron's topological charge.
This helps clarify the tunneling interpretation of these solutions, and their
relation to Chern-Simons numbers and winding numbers.Comment: 10 pages, 10 figures, a sign typo in equation 27 is correcte
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