Nonclassical Degrees of Freedom in the Riemann Hamiltonian

The Hilbert-Polya conjecture states that the imaginary parts of the zeros of the Riemann zeta function are eigenvalues of a quantum hamiltonian. If so, conjectures by Katz and Sarnak put this hamiltonian in Altland and Zirnbauer's universality class C. This implies that the system must have a nonclassical two-valued degree of freedom. In such a system, the dominant primitive periodic orbits contribute to the density of states with a phase factor of -1. This resolves a previously mysterious sign problem with the oscillatory contributions to the density of the Riemann zeros.Comment: 4 pages, no figures; v3-6 have minor corrections to v2, v2 has a more complete solution of the sign problem than v

Impulse control disorders in non-treatment seeking hair pullers

Background and aims: Hair pulling is a common body focused repetitive behavior. The purpose of this paper is to examine the prevalence of impulse control disorders (as defined in DSM-IV-TR) in a non-treatment seeking sample of hair pullers. Methods: 1,717 college students with (n = 44) and without (n = 1673) hair pulling completed a mental health survey. The college students were sent an online survey assessing hair pulling behavior and other impulse control disorders using the Minnesota Impulsive Disorders Interview. Results: Students with hair pulling were significantly more likely to have a co-occurring impulse control disorder (20.5% vs. 8.9%, p = 0.009, OR = 2.71, CI = 1.28–5.75) and were significantly more likely to meet criteria for compulsive buying, compulsive sexual behavior and intermittent explosive disorder than students without hair pulling. Differences seemed to be moderated by the male gender among students with hair pulling. Discussion and conclusions: Hair pulling is often comorbid with another impulse control disorder, which suggests that elements of impulsivity may be important in our understanding of hair pulling. Furthermore, gender may moderate impulse control comorbidity in hair pulling disorder

Sleepiness and cognition in young adults who gamble and use alcohol

Abstract Background and aims Past research suggests that sleep problems are associated with increased risky decision-making. Similarly, gambling disorder and alcohol use disorder are also associated with increased risky decision-making. Individuals with gambling disorder or alcohol use disorder have also reported higher rates of sleep problems compared to normal healthy controls. As such, we sought to examine whether sleep problems play a role in the development of alcohol use disorder or gambling disorder. Methods One hundred and forty-one individuals who gamble and use alcohol, yet do not meet criteria for gambling disorder or alcohol use disorder, were assessed to determine the correlation between sleepiness, amount of sleep obtained, decision-making, and alcohol or gambling behaviors. Results Our results suggest that inconsistent sleep patterns may be associated with increased frequency of alcohol use and gambling. We did not, however, find a significant correlation between sleep factors and decision-making. Discussion Further research is needed to examine the specific relationship between sleep patterns and alcohol use and gambling frequency. Overall these data suggest that sleepiness or sleep and risky decision-making is not a significant factor in gambling and alcohol use behaviors in individuals not meeting criteria for alcohol use disorder or gambling disorder

The Berry-Keating Hamiltonian and the Local Riemann Hypothesis

The local Riemann hypothesis states that the zeros of the Mellin transform of a harmonic-oscillator eigenfunction (on a real or p-adic configuration space) have real part 1/2. For the real case, we show that the imaginary parts of these zeros are the eigenvalues of the Berry-Keating hamiltonian H=(xp+px)/2 projected onto the subspace of oscillator eigenfunctions of lower level. This gives a spectral proof of the local Riemann hypothesis for the reals, in the spirit of the Hilbert-Polya conjecture. The p-adic case is also discussed.Comment: 9 pages, no figures; v2 included more mathematical background, v3 has minor edits for clarit

Damage function for historic paper. Part I: Fitness for use

Background In heritage science literature and in preventive conservation practice, damage functions are used to model material behaviour and specifically damage (unacceptable change), as a result of the presence of a stressor over time. For such functions to be of use in the context of collection management, it is important to define a range of parameters, such as who the stakeholders are (e.g. the public, curators, researchers), the mode of use (e.g. display, storage, manual handling), the long-term planning horizon (i.e. when in the future it is deemed acceptable for an item to become damaged or unfit for use), and what the threshold of damage is, i.e. extent of physical change assessed as damage. Results In this paper, we explore the threshold of fitness for use for archival and library paper documents used for display or reading in the context of access in reading rooms by the general public. Change is considered in the context of discolouration and mechanical deterioration such as tears and missing pieces: forms of physical deterioration that accumulate with time in libraries and archives. We also explore whether the threshold fitness for use is defined differently for objects perceived to be of different value, and for different modes of use. The data were collected in a series of fitness-for-use workshops carried out with readers/visitors in heritage institutions using principles of Design of Experiments. Conclusions The results show that when no particular value is pre-assigned to an archival or library document, missing pieces influenced readers/visitors’ subjective judgements of fitness-for-use to a greater extent than did discolouration and tears (which had little or no influence). This finding was most apparent in the display context in comparison to the reading room context. The finding also best applied when readers/visitors were not given a value scenario (in comparison to when they were asked to think about the document having personal or historic value). It can be estimated that, in general, items become unfit when text is evidently missing. However, if the visitor/reader is prompted to think of a document in terms of its historic value, then change in a document has little impact on fitness for use

Application of the microhole and strip plate detector for neutron detection

We introduce the microhole and strip plate (MHSP) detector as a micropattern detector for the detection of thermal and epithermal neutrons. Detection sensitivity is obtained by filling these detectors with 3He at high pressures. We propose the use of argon-xenon penning mixtures as the stopping gas as opposed to the usual carbon based stopping gases. These argon-xenon mixtures provide suitable gas gains for the high pressure/high resolution neutron detector applications. With these mixtures it is possible to obtain a sealed detector with only rare-gas filling which is simple to purify and not subject to ageing. An MHSP gas detector filled with a 3-bar argon/50-mbar xenon/6-bar helium mixture can achieve gains above 2×103. This mixture allows neutron detection efficiencies of about 70% at 1 Å for a 2.5-cm thick absorption region and intrinsic position resolution (full-width at half-maximum) of about 1.8 mm. The sensitivity to γ-rays of the present mixture will be the same when compared to that of 2.6-bar CF

Application of the microhole and strip plate detector for neutron detection

We introduce the microhole and strip plate (MHSP) detector as a micropattern detector for the detection of thermal and epithermal neutrons. Detection sensitivity is obtained by filling these detectors with 3He at high pressures. We propose the use of argon-xenon penning mixtures as the stopping gas as opposed to the usual carbon based stopping gases. These argon-xenon mixtures provide suitable gas gains for the high pressure/high resolution neutron detector applications. With these mixtures it is possible to obtain a sealed detector with only rare-gas filling which is simple to purify and not subject to ageing. An MHSP gas detector filled with a 3-bar argon/50-mbar xenon/6-bar helium mixture can achieve gains above 2×103. This mixture allows neutron detection efficiencies of about 70% at 1 Å for a 2.5-cm thick absorption region and intrinsic position resolution (full-width at half-maximum) of about 1.8 mm. The sensitivity to γ-rays of the present mixture will be the same when compared to that of 2.6-bar CF

PCaaD:Towards automated determination and exploitation of industrial systems

Over the last decade, Programmable Logic Controllers (PLCs) have been increasingly targeted by attackers to obtain control over industrial processes that support critical services. Such targeted attacks typically require detailed knowledge of system-specific attributes, including hardware configurations, adopted protocols, and PLC control-logic, i.e., process comprehension. The consensus from both academics and practitioners suggests stealthy process comprehension obtained from a PLC alone, to execute targeted attacks, is impractical. In contrast, we assert that current PLC programming practices open the door to a new vulnerability class, affording attackers an increased level of process comprehension. To support this, we propose the concept of Process Comprehension at a Distance (PCaaD), as a novel methodological and automatable approach towards the system-agnostic identification of PLC library functions. This leads to the targeted exfiltration of operational data, manipulation of control-logic behavior, and establishment of covert command and control channels through unused memory. We validate PCaaD on widely used PLCs through its practical application

Near-Field Pressure Signature Splicing for Low-Fidelity Design Space Exploration of Supersonic Aircraft

As interest in supersonic overland flight intensifies, new ways to meet government restrictions on sonic boom loudness must be implemented. Low-fidelity aerodynamic tools, such as PANAIR, can estimate the near-field pressure signature that ultimately determines the loudness of the sonic boom at the ground. These tools can greatly benefit the exploration of large design spaces due to their computational efficiency. One of the limitations of low-fidelity tools is the accuracy of the solution produced, which is dependent on the fundamental physical assumptions made in the development of the governing equations. If flow patterns are produced that severely violate these fundamental assumptions, the validity of the near-field pressure signature is compromised. A method is proposed that splices together near-field pressure signatures from a low-fidelity and a higher-fidelity tool by cutting each pressure signature at a critical point and then blending the low-fidelity signature into the higher-fidelity signature. By splicing the signatures together, sections of the low-fidelity signature that represent fundamental violations of the governing equation are removed. This method allows for the exploration of the design space corresponding to areas on the geometry that produce accurate results in a low-fidelity signature. The method is tested on the JAXA Wing Body geometry from the Second AIAA Sonic Boom Prediction Workshop and shows that perturbations to this geometry can produce loudness results that match the high-fidelity results to within 0.4 PLdB