New Sources of Gravitational Waves during Inflation

We point out that detectable inflationary tensor modes can be generated by particle or string sources produced during inflation, consistently with the requirements for inflation and constraints from scalar fluctuations. We show via examples that this effect can dominate over the contribution from quantum fluctuations of the metric, occurring even when the inflationary potential energy is too low to produce a comparable signal. Thus a detection of tensor modes from inflation does not automatically constitute a determination of the inflationary Hubble scale.Comment: 32 pages, 1 figure. v2: JCAP published version; some overestimates corrected; main results unchange

Information Leakage Games

We consider a game-theoretic setting to model the interplay between attacker and defender in the context of information flow, and to reason about their optimal strategies. In contrast with standard game theory, in our games the utility of a mixed strategy is a convex function of the distribution on the defender's pure actions, rather than the expected value of their utilities. Nevertheless, the important properties of game theory, notably the existence of a Nash equilibrium, still hold for our (zero-sum) leakage games, and we provide algorithms to compute the corresponding optimal strategies. As typical in (simultaneous) game theory, the optimal strategy is usually mixed, i.e., probabilistic, for both the attacker and the defender. From the point of view of information flow, this was to be expected in the case of the defender, since it is well known that randomization at the level of the system design may help to reduce information leaks. Regarding the attacker, however, this seems the first work (w.r.t. the literature in information flow) proving formally that in certain cases the optimal attack strategy is necessarily probabilistic

Evaluation of thyroid hormones in patients with lead poisoning

Background: Each toxic agent results in unique presentations, depending on what neurophysiological changes occur following exposure. Scientific understanding of lead toxicity in the organ systems and at low levels of exposure continues to evolve. However, effects of lead poisoning on the thyroid gland function are controversial. In this descriptive study, changes in thyroid hormones in patients with lead poisoning were compared with patients with opioid addiction and healthy individual who were matched for age and sex. Methods: In this descriptive study, which was conducted from March 2016 to February 2017 in Loghman Hakim Hospital in Tehran, ninety patients were evaluated using convenient sampling method for lead and thyroid hormones levels. The levels of lead and thyroid hormones were evaluated using standard laboratory method, in thirty male patients with lead poisoning, thirty male patients with opioid addiction referring to addiction treatment center and thirty healthy male referring to a blood donation center who were matcAhed for age. Thyroid function parameters in patients with lead toxicity were compared with those of control groups. Results: The lead level in the lead toxicity group was 57.5±23.5 µg/dl, in the first control group with opium addiction 7.8±3.8 µg/dl and in the healthy male referring to a blood donation center, 5.9±9 µg/dl. Thyroid stimulating hormone (TSH) was significantly lower in patients with lead poisoning (0.2±0.01 Milli-International Units Per Liter (mIU/L) than in the patients with opioid addiction (2.4±1/05 mIU/L) and healthy male referring to a blood donation center (2.3±0.01 mIU/L) (P= 0.04), and thyroxine hormone (T4) was significantly higher in patients with lead poisoning (17.8±2.6 µg/dl) than in the patients with opioid addiction (8.8±1/9 µg/dl) and healthy male referring to a blood donation center (7.4±3.5 µg/dl) (P= 0.02). Conclusion: Lead toxicity has an effect on thyroid function and it reduces thyroid stimulating hormone and increases thyroxin levels. Clinicians should be aware of the potential hazardous effects of lead on the thyroid and mechanisms through which lead causes these effects on thyroid function need to be elucidated. Keywords: lead poisoning, opium, thyroid function test

Beyond Logarithmic Corrections to Cardy Formula

As shown by Cardy modular invariance of the partition function of a given unitary non-singular 2d CFT with left and right central charges c_L and c_R, implies that the density of states in a microcanonical ensemble, at excitations Delta and Delta-bar and in the saddle point approximation, is \rho_0(\Delta,\bar\Delta;c_L, c_R)=c_L c_R \exp(2\pi\sqrt{{c_L\Delta}/{6}})\exp(2\pi\sqrt{{c_R\bar\Delta}/{6}}). In this paper, we extend Cardy's analysis and show that in the saddle point approximation and up to contributions which are exponentially suppressed compared to the leading Cardy's result, the density of states takes the form \rho(\Delta,\bar\Delta; c_L,c_R)= f(c_L\Delta) f(c_R\bar\Delta)\rho_0(\Delta,\bar\Delta; c_L, c_R), for a function f(x) which we specify. In particular, we show that (i) \rho (\Delta,\bar\Delta; c_L, c_R) is the product of contributions of left and right movers and hence, to this approximation, the partition function of any modular invariant, non-singular unitary 2d CFT is holomorphically factorizable and (ii) \rho(\Delta,\bar\Delta; c_L, c_R)/(c_Lc_R) is only a function of $c_R\bar\Delta$ and $c_L\Delta$. In addition, treating \rho(\Delta,\bar\Delta; c_L, c_R) as the density of states of a microcanonical ensemble, we compute the entropy of the system in the canonical counterpart and show that the function f(x) is such that the canonical entropy, up to exponentially suppressed contributions, is simply given by the Cardy's result \ln\rho_0(\Delta,\bar\Delta; c_L, c_R).Comment: 30 pages, no figures; v2: minor improvements, one reference added, v3: minor corrections to match the published versio

Force transmission in a packing of pentagonal particles

We perform a detailed analysis of the contact force network in a dense confined packing of pentagonal particles simulated by means of the contact dynamics method. The effect of particle shape is evidenced by comparing the data from pentagon packing and from a packing with identical characteristics except for the circular shape of the particles. A counterintuitive finding of this work is that, under steady shearing, the pentagon packing develops a lower structural anisotropy than the disk packing. We show that this weakness is compensated by a higher force anisotropy, leading to enhanced shear strength of the pentagon packing. We revisit "strong" and "weak" force networks in the pentagon packing, but our simulation data provide also evidence for a large class of "very weak" forces carried mainly by vertex-to-edge contacts. The strong force chains are mostly composed of edge-to-edge contacts with a marked zig-zag aspect and a decreasing exponential probability distribution as in a disk packing

Credit card fraud detection using asexual reproduction optimization

Purpose – The best algorithm that was implemented on this Brazilian dataset was artificial immune system (AIS) algorithm. But the time and cost of this algorithm are high. Using asexual reproduction optimization (ARO) algorithm, the authors achieved better results in less time. So the authors achieved less cost in a shorter time. Their framework addressed the problems such as high costs and training time in credit card fraud detection. This simple and effective approach has achieved better results than the best techniques implemented on our dataset so far. The purpose of this paper is to detect credit card fraud using ARO. Design/methodology/approach – In this paper, the authors used ARO algorithm to classify the bank transactions into fraud and legitimate. ARO is taken from asexual reproduction. Asexual reproduction refers to a kind of production in which one parent produces offspring identical to herself. In ARO algorithm, an individual is shown by a vector of variables. Each variable is considered as a chromosome. A binary string represents a chromosome consisted of genes. It is supposed that every generated answer exists in the environment, and because of limited resources, only the best solution can remain alive. The algorithm starts with a random individual in the answer scope. This parent reproduces the offspring named bud. Either the parent or the offspring can survive. In this competition, the one which outperforms in fitness function remains alive. If the offspring has suitable performance,it will be the next parent, and the current parent becomes obsolete.Otherwise, the offspring perishes, and the present parent survives. The algorithm recurs until the stop condition occurs. Findings – Results showed that ARO had increased the AUC (i.e. area under a receiver operating characteristic (ROC) curve), sensitivity, precision, specificity and accuracy by 13%, 25%, 56%, 3% and 3%, in comparison with AIS, respectively. The authors achieved a high precision value indicating that if ARO detects a record as a fraud, with a high probability, it is a fraud one. Supporting a real-time fraud detection system is another vital issue. ARO outperforms AIS not only in the mentioned criteria, but also decreases the training time by 75% in comparison with the AIS, which is a significant figure. Originality/value – In this paper, the authors implemented the ARO in credit card fraud detection. The authors compared the results with those of the AIS, which was one of the best methods ever implemented on the benchmark dataset. The chief focus of the fraud detection studies is finding the algorithms that can detect legal transactions from the fraudulent ones with high detection accuracy in the shortest time and at a low cost. That ARO meets all these demands

Near the horizon of 5D black rings

For the five dimensional N=2 black rings, we study the supersymmetry enhancement and identify the global supergroup of the near horizon geometry. We show that the global part of the supergroup is OSp(4*|2)X U(1) which is similar to the small black string. We show that results obtained by applying the entropy function formalism, the c-extremization approach and the Brown-Henneaux method to the black ring solution are in agreement with the microscopic entropy calculation.Comment: 26 pages, version to appear in JHEP, the near horizon superalgebra is corrected, discussion on small black ring is discarded, Brown-Henneaux approach to large black ring is adde