Physical Sciences and Mathematics Commons^™

The Close Agn Reference Survey (Cars): Ifu Survey Data And The Bh Mass Dependence Of Long-Term Agn Variability, B. Husemann, M. Singha, J. Scharwächter, R. Mcelroy, J. Neumann, I. Smirnova-Pinchukova, T. Urrutia, S. A. Baum, V. N. Bennert, F. Combes, S. M. Croom, T. A. Davis, Y. Fournier, A. Galkin, M. Gaspari, H. Enke, M. Krumpe, C. P. O'Dea, M. Pérez-Torres, T. Rose, G. R. Tremblay, C. J. Walcher

Physics

Context. Active galactic nuclei (AGN) are thought to be intimately connected with their host galaxies through feeding and feedback processes. A strong coupling is predicted and supported by cosmological simulations of galaxy formation, but the details of the physical mechanisms are still observationally unconstrained.

Aims. Galaxies are complex systems of stars and a multiphase interstellar medium (ISM). A spatially resolved multiwavelength survey is required to map the interaction of AGN with their host galaxies on different spatial scales and different phases of the ISM. The goal of the Close AGN Reference Survey (CARS) is to obtain the necessary spatially resolved …

Erratum: Search For Heavy Higgs Bosons Decaying To A Top Quark Pair In Proton-Proton Collisions At S = 13 Tev (Journal Of High Energy Physics, (2020), 2020, 4, (171), 10.1007/Jhep04(2020)171), The Cms Collaboration, A. M. Sirunyan, A. Tumasyan, W. Adam, F. Ambrogi, T. Bergauer, Julie M. Hogan

Physics and Engineering Faculty Publications

In figure 7 of the original publication, the label of the y axis should have been (Formula presented.)”. The corrected version is shown in figure 1. Accordingly, the text pointing to the figure should read “figure 7 shows scans of (Formula presented.) for this hypothesis, as a function of the coupling modifier gAtt-”.

Measurement Of W±Γ Differential Cross Sections In Proton-Proton Collisions At S =13 Tev And Effective Field Theory Constraints, The Cms Collaboration, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, Julie M. Hogan

Physics and Engineering Faculty Publications

Differential cross section measurements of W±γ production in proton-proton collisions at s=13 TeV are presented. The data set used in this study was collected with the CMS detector at the CERN LHC in 2016-2018 with an integrated luminosity of 138 fb-1. Candidate events containing an electron or muon, a photon, and missing transverse momentum are selected. The measurements are compared with standard model predictions computed at next-to-leading and next-to-next-to-leading orders in perturbative quantum chromodynamics. Constraints on the presence of TeV-scale new physics affecting the WWγ vertex are determined within an effective field theory framework, focusing on the O3W operator. A …

90snet:, Seth Richard

Honors Theses

No abstract provided.

Peak Chlorophyll A Concentrations In The Lower Mississippi River From 1997 To 2018, R. Eugene Turner, Charles S. Milan, Erick M. Swenson, James M. Lee

Faculty Publications

Large and turbid rivers have varying temperatures, light conditions, nutrient availability, and nutrient ratios that may affect phytoplankton communities and occur within a changing world of point and nonpoint source nutrient loadings. We investigated how these physical and chemical factors affect Chlorophyll a (Chl a) concentrations in the Mississippi River, the largest river in North America, by sampling 878 times from February 1997 to December 2018 near its terminus at Baton Rouge, Louisiana. We hypothesized that nutrient concentrations and ratios were significant factors limiting phytoplankton biomass accumulations in this turbid river. The Chl a concentrations were in the "poor" water …

Experiment 2.05: Wheatstone Bridge, Diego Castano

Physics Lab Experiments with Simulated Data for Remote Delivery

The Wheatstone Bridge is used to determine the resistances of five resistors.

Experiment 2.04: Kirchhoff’S Laws, Diego Castano, Andrew Kiene

Physics Lab Experiments with Simulated Data for Remote Delivery

A non-trivial resistor arrangement is analyzed

Experiment 2.06: Series Rc Dc-Circuit, Diego Castano, Victor Castro

Physics Lab Experiments with Simulated Data for Remote Delivery

The capacitances of two unknown capacitors are determined examining their charging behavior.

Experiment 2.02: Electric And Potential Fields, Diego Castano

Physics Lab Experiments with Simulated Data for Remote Delivery

Electric field line maps for three 2-dimensional charge distributions are determined using a voltmeter.

Experiment 2.03: Ohm’S Law, Diego Castano, Victor Castro

Physics Lab Experiments with Simulated Data for Remote Delivery

The resistances of three resistors are determined by varying the applied voltage and measuring the resulting current.

Experiment 2.01: Coulomb’S Law, Diego Castano

Physics Lab Experiments with Simulated Data for Remote Delivery

The charge resulting from the static electrification of a Teflon plate is determined through its interaction with a neutral conducting sphere.

Experiment 2.09: Reflection And Refraction, Diego Castano, Victor Castro

Physics Lab Experiments with Simulated Data for Remote Delivery

The laws of geometrical optics are studied by tracking light rays refracting across an air-glass boundary and reflecting off convex and concave mirrors.

Experiment 2.08: Series Rlc Ac-Circuit, Diego Castano, Victor Castro

Physics Lab Experiments with Simulated Data for Remote Delivery

Using the resonant behavior of a circuit consisting of a coil and known capacitor, the coil’s self-inductance and resistance are determined.

Experiment 2.07: Magnetic Field Of The Earth, Diego Castano, Victor Castro

Physics Lab Experiments with Simulated Data for Remote Delivery

The earth’s horizontal component of magnetic field is determined using a tangent galvanometer.

Experiment 2.10: Lenses, Diego Castano, Victor Castro

Physics Lab Experiments with Simulated Data for Remote Delivery

The focal lengths of converging and diverging lenses are determined.

Why Menzerath's Law?, Julio Urenda, Vladik Kreinovich

Departmental Technical Reports (CS)

In linguistics, there is a dependence between the length of the sentence and the average length of the word: the longer the sentence, the shorter the words. The corresponding empirical formula is known as the Menzerath's Law. A similar dependence can be observed in many other application areas, e.g., in the analysis of genomes. The fact that the same dependence is observed in many different application domains seems to indicate there should be a general domain-independent explanation for this law. In this paper, we show that indeed, this law can be derived from natural invariance requirements.

How To Solve The Apportionment Paradox, Christopher Reyes, Vladik Kreinovich

Departmental Technical Reports (CS)

In the ideal world, the number of seats that each region or each community gets in a representative body should be exactly proportional to the population of this region or community. However, since the number of seats allocated to each region or community is whole, we cannot maintain the exact proportionality. Not only this leads to a somewhat unfair situation, when residents of one region get more votes per person than residents of another one, it also leads to paradoxes -- e.g., sometimes a region that gained the largest number of people loses a number of seats. To avoid this …

Why Hate: Analysis Based On Decision Theory, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

At first glance, from the general decision-theory viewpoint, hate (and other negative feelings towards each other) makes no sense, since they decrease the utility (i.e., crudely speaking, level of happiness) of the person who experiences these feelings. Our detailed analysis shows that there are situations when such negative feelings make perfect sense: namely, when you have a large group of people almost all of whom are objectively unhappy. In such situations -- e.g., on the battlefield -- negative feelings help keep their spirits high in spite of the harsh situation. This explanation leads to recommendations on how to decrease the …

How To Solve The Apportionment Paradox, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

It is known that often, after it is proven that a new statement is equivalent to the original definition, this new statement becomes the accepted new definition of the same notion. In this paper, we provide a natural explanation for this empirical phenomenon.

How To Describe Hypothetic Truly Rare Events (With Probability 0), Luc Longpre, Vladik Kreinovich

Departmental Technical Reports (CS)

In probability theory, rare events are usually described as events with low probability p, i.e., events for which in N observations, the event happens n(N) ~ p*N times. Physicists and philosophers suggested that there may be events which are even rarer, in which n(N) grows slower than N. However, this idea has not been developed, since it was not clear how to describe it in precise terms. In this paper, we propose a possible precise description of this idea, and we use this description to answer a natural question: when two different functions n(N) lead to the same class of …

How To Make Quantum Ideas Less Counter-Intuitive: A Simple Analysis Of Measurement Uncertainty Can Help, Olga Kosheleva, Vladik Kreinovich, Louis Ray Lopez

Departmental Technical Reports (CS)

Our intuition about physics is based on macro-scale phenomena, phenomena which are well described by non-quantum physics. As a result, many quantum ideas sound counter-intuitive -- and this slows down students' learning of quantum physics. In this paper, we show that a simple analysis of measurement uncertainty can make many of the quantum ideas much less counter-intuitive and thus, much easier to accept and understand.

Shall We Use Logical Approach Or More Traditional Mamdani Approach In Fuzzy Control: Pragmatic Analysis, R. Noah Padilla, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

Fuzzy control methodology transforms the experts' if-then rules into a precise control strategy. From the logical viewpoint, an if-then rule means implication, so it seems reasonable to use fuzzy implication in this transformation. However, this logical approach is not what the first fuzzy controllers used. The traditional fuzzy control approach -- first proposed by Mamdani -- transforms the if-then rules into a statement that only contains and's and or's, and does not use fuzzy implication at all. So, a natural question arises: shall we use logical approach or the traditional approach? In this paper, we analyze this question on the …

Why Deep Neural Networks: Yet Another Explanation, Ricardo Lozano, Ivan Montoya Sanchez, Vladik Kreinovich

Departmental Technical Reports (CS)

One of the main motivations for using artificial neural networks was to speed up computations. From this viewpoint, the ideal configuration is when we have a single nonlinear layer: this configuration is computationally the fastest, and it already has the desired universal approximation property. However, the last decades have shown that for many problems, deep neural networks, with several nonlinear layers, are much more effective. How can we explain this puzzling fact? In this paper, we provide a possible explanation for this phenomena: that the universal approximation property is only true in the idealized setting, when we assume that all …

Why Optimization Is Faster Than Solving Systems Of Equations: A Qualitative Explanation, Siyu Deng, Bimal K. C, Vladik Kreinovich

Departmental Technical Reports (CS)

Most practical problems lead either to solving a system of equation or to optimization. From the computational viewpoint, both classes of problems can be reduced to each other: optimization can be reduced to finding points at which all partial derivatives are zeros, and solving systems of equations can be reduced to minimizing sums of squares. It is therefore natural to expect that, on average, both classes of problems have the same computational complexity -- i.e., require about the same computation time. However, empirically, optimization problems are much faster to solve. In this paper, we provide a possible explanation for this …

Spiral Arms Around A Star: Geometric Explanation, Juan L. Puebla, Vladik Kreinovich

Departmental Technical Reports (CS)

Recently, astronomers discovered spiral arms around a star. While their shape is similar to the shape of the spiral arms in the galaxies, however, because of the different scale, galaxy-related physical explanations of galactic spirals cannot be directly applied to explaining star-size spiral arms. In this paper, we show that, in contrast to more specific physical explanation, more general symmetry-based geometric explanations of galactic spiral can explain spiral arms around a star.

Why Self-Esteem Helps To Solve Problems: An Algorithmic Explanation, Oscar Ortiz, Henry Salgado, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

It is known that self-esteem helps solve problems. From the algorithmic viewpoint, this seems like a mystery: a boost in self-esteem does not provide us with new algorithms, does not provide us with ability to compute faster -- but somehow, with the same algorithmic tools and the same ability to perform the corresponding computations, students become better problem solvers. In this paper, we provide an algorithmic explanation for this surprising empirical phenomenon.

Why Immunodepressive Drugs Often Make People Happier, Joshua Ramos, Dario Vasquez, Ruth Trejo, Vladik Kreinovich

Departmental Technical Reports (CS)

Many immunodepressive drugs have an unusual side effect on the patient's mood: they often make the patient happier. This side hae been observed for many different immunodepressive drugs, with different chemical composition. Thus, it is natural to conclude that there must be some general reason for this empirical phenomenon, a reason not related to the chemical composition of any specific drug -- but rather with their general functionality. In this paper, we provide such an explanation.

Explaining An Empirical Formula For Bioreaction To Similar Stimuli (Covid-19 And Beyond), Olga Kosheleva, Vladik Kreinovich, Nguyen Hoang Phuong

Departmental Technical Reports (CS)

A recent comparative analysis of biological reaction to unchanging vs. rapidly changing stimuli -- such as Covid-19 or flu viruses -- uses an empirical formula describing how the reaction to a similar stimulus depends on the distance between the new and original stimuli. In this paper, we provide a from-first-principles explanation for this empirical formula.

An Introduction To Number Theory, J. J. P. Veerman

PDXOpen: Open Educational Resources

These notes are intended for a graduate course in Number Theory. No prior familiarity with number theory is assumed.

Chapters 1-14 represent almost 3 trimesters of the course. Eventually we intend to publish a full year (3 trimesters) course on number theory. The current content represents courses the author taught in the academic years 2020-2021 and 2021-2022.

It is a work in progress. If you have questions or comments, please contact Peter Veerman (veerman@pdx.edu).

Study Of Dijet Events With Large Rapidity Separation In Proton-Proton Collisions At √S = 2.76 Tev, The Cms Collaboration, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, Julie M. Hogan

Physics and Engineering Faculty Publications

The cross sections for inclusive and Mueller-Navelet dijet production are measured as a function of the rapidity separation between the jets in proton-proton collisions at s = 2.76 TeV for jets with transverse momentum pT> 35 GeV and rapidity |y| < 4.7. Various dijet production cross section ratios are also measured. A veto on additional jets with pT> 20 GeV is introduced to improve the sensitivity to the effects of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) evolution. The measurement is compared with the predictions of various Monte Carlo models based on leading-order and next-to-leading-order calculations including the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi leading-logarithm (LL) parton shower as well as the LL BFKL resummation. [Figure not available: see fulltext.]