# Physics Commons™

## All Articles in Physics

26127 full-text articles. Page 1 of 665.

Recursive Non-Local Means Filter For Video Denoising, 2017 University of Dayton

#### Recursive Non-Local Means Filter For Video Denoising, Redha A. Ali, Russell C. Hardie

##### Electrical and Computer Engineering Faculty Publications

In this paper, we propose a computationally efficient algorithm for video denoising that exploits temporal and spatial redundancy. The proposed method is based on non-local means (NLM). NLM methods have been applied successfully in various image denoising applications. In the single-frame NLM method, each output pixel is formed as a weighted sum of the center pixels of neighboring patches, within a given search window.

The weights are based on the patch intensity vector distances. The process requires computing vector distances for all of the patches in the search window. Direct extension of this method from 2D to 3D, for video ...

Climate Change, Development, And The Global Commons, 2017 University of Dayton

#### Climate Change, Development, And The Global Commons, Robert J. Brecha

##### The Social Practice of Human Rights: Charting the Frontiers of Research and Advocacy

An important link between energy, climate change, human development, and human rights comes in the form of a question that has yet to be answered satisfactorily: The earth’s atmosphere and other physical systems are the ultimate example of the global commons. Do future generations have a human right to an unchanged earth system? Sustainable Development Goals 13, 14, and 15 imply an affirmative answer. Given that climate scientists have a good estimate of the amount of carbon dioxide that can be emitted before the safe uptake capacity of the atmosphere is breached, how do we allocate that remaining atmospheric ...

2017 Institute of problems of Chemical Physics, Russia

#### Discrete Space-Time Model For Heat Conduction: Application To Sizedependent Thermal Conductivity In Nano-Films, Sergey Sobolev

##### Sergey Sobolev

No abstract provided.

2017 The Graduate Center, City University of New York

#### Detecting Majorana Fermion Induced Crossed Andreev Reflection, Lei Fang

##### All Graduate Works by Year: Dissertations, Theses, and Capstone Projects

This dissertation is devoted to a study of detecting the Majorana fermion induced crossed Andreev reflection.

Majorana fermions are particles that constitute their own antiparticles. In condensed matter physics, Majorana fermions are zero energy modes that reside at edges or around vortices of topological superconductors. The special properties of Majorana fermions result in their potential to conduct topological quantum computation, which has been attracting a lot of current research. One of the most important issues in the field of the Majorana fermion physics now is to detect their existence in realistic systems. Among many classes of detecting methods, a transport ...

Modification Of The G-Phonon Mode Of Graphene By Nitrogen Doping, 2017 University of Nothern Iowa

#### Modification Of The G-Phonon Mode Of Graphene By Nitrogen Doping, Pavel V. Lukashev, Liuyan Zhao, Tula R. Paudel, Theanne Schiros, Noah Hurley, Evgeny Y. Tsymbal, Aron Pinczuk, Abhay Pasupathy, Rui He

##### Pavel Lukashev

The effect of nitrogen doping on the phonon spectra of graphene is analyzed. In particular, we employ first-principles calculations and scanning Raman analysis to investigate the dependence of phonon frequencies in graphene on the concentration of nitrogen dopants. We demonstrate that the G phonon frequency shows oscillatory behavior as a function of nitrogen concentration. We analyze different mechanisms which could potentially be responsible for this behavior, such as Friedel charge oscillations around the localized nitrogen impurity atom, the bond length change between nitrogen impurity and its nearest neighbor carbon atoms, and the long-range interactions of the nitrogen point defects. We ...

2017 University of Northern Iowa

#### Simple, Complete, And Novel Quantitative Model Of Holography For Students Of Science And Science Education, Dale Olson

##### Dale W. Olson

A Moiré graphical method for predicting the directions of all permitted image waves for thin and volume holograms is described. This method has been developed in connection with a holography centred optics course for students in science, technology and science education that has evolved over several decades. A somewhat unique view of the holographic process underlies this novel method of predicting the behaviour of diffraction gratings.

Modification Of The G-Phonon Mode Of Graphene By Nitrogen Doping, 2017 University of Nothern Iowa

#### Modification Of The G-Phonon Mode Of Graphene By Nitrogen Doping, Pavel V. Lukashev, Liuyan Zhao, Tula R. Paudel, Theanne Schiros, Noah Hurley, Evgeny Y. Tsymbal, Aron Pinczuk, Abhay Pasupathy, Rui He

##### Rui He

The effect of nitrogen doping on the phonon spectra of graphene is analyzed. In particular, we employ first-principles calculations and scanning Raman analysis to investigate the dependence of phonon frequencies in graphene on the concentration of nitrogen dopants. We demonstrate that the G phonon frequency shows oscillatory behavior as a function of nitrogen concentration. We analyze different mechanisms which could potentially be responsible for this behavior, such as Friedel charge oscillations around the localized nitrogen impurity atom, the bond length change between nitrogen impurity and its nearest neighbor carbon atoms, and the long-range interactions of the nitrogen point defects. We ...

Modification Of The G-Phonon Mode Of Graphene By Nitrogen Doping, 2017 University of Nothern Iowa

#### Modification Of The G-Phonon Mode Of Graphene By Nitrogen Doping, Pavel V. Lukashev, Liuyan Zhao, Tula R. Paudel, Theanne Schiros, Noah Hurley, Evgeny Y. Tsymbal, Aron Pinczuk, Abhay Pasupathy, Rui He

##### Rui He

The effect of nitrogen doping on the phonon spectra of graphene is analyzed. In particular, we employ first-principles calculations and scanning Raman analysis to investigate the dependence of phonon frequencies in graphene on the concentration of nitrogen dopants. We demonstrate that the G phonon frequency shows oscillatory behavior as a function of nitrogen concentration. We analyze different mechanisms which could potentially be responsible for this behavior, such as Friedel charge oscillations around the localized nitrogen impurity atom, the bond length change between nitrogen impurity and its nearest neighbor carbon atoms, and the long-range interactions of the nitrogen point defects. We ...

2017 Utah State University

#### Fundamental Coupling Processes In The Mesosphere, Lower Thermosphere (Mlt) Using Enhanced Na Wind-Temperature Lidar Measurements At The Atmospheric Lidar Observatory, Titus Yuan

##### Funded Research and Data

No abstract provided.

2017 Loyola Marymount University

#### Fractal Holography: A Geometric Re-Interpretation Of Cosmological Large Scale Structure, Jonas R. Mureika

##### Jonas Mureika

The fractal dimension of large-scale galaxy clustering has been demonstrated to be roughly DF∼2 from a wide range of redshift surveys. If correct, this statistic is of interest for two main reasons: fractal scaling is an implicit representation of information content, and also the value itself is a geometric signature of area. It is proposed that the fractal distribution of galaxies may thus be interpreted as a signature of holography (fractal holography''), providing more support for current theories of holographic cosmologies. Implications for entropy bounds are addressed. In particular, because of spatial scale invariance in the matter distribution ...

2017 Loyola Marymount University

#### Differentiating Unparticles From Extra Dimensions Via Mini Black Hole Thermodynamics, Jonas R. Mureika

##### Jonas Mureika

A thermodynamics-based method is presented for differentiating mini black hole creation mechanisms in high energy parton collisions, including scenarios with large compactified extra dimensions and unparticle-enhanced gravity with real scaling dimension dU. Tensor unparticle interactions are shown to mimic the physics of (2dU−2) noninteger extra spatial dimensions. This yields unique model-dependent production rates, Hawking temperature profiles, and decay multiplicities for black holes of mass MBH∼1–15  TeV that may be created at the LHC and other future colliders.

Vector Unparticle Enhanced Black Holes: Exact Solutions And Thermodynamics, 2017 Loyola Marymount University

#### Vector Unparticle Enhanced Black Holes: Exact Solutions And Thermodynamics, Jonas R. Mureika, Euro Spallucci

##### Jonas Mureika

Tensor and scalar unparticle couplings to matter have been shown to enhance gravitational interactions and provide corrections to the Schwarzschild metric and associated black hole structure. We derive an exact solution to the Einstein equations for vector unparticles, and conclusively demonstrate that these induce Riessner–Nordström (RN)-like solutions where the role of the “charge” is defined by a composite of unparticle phase space parameters. These black holes admit double-horizon structure, although unlike the RN metric these solutions have a minimum inner horizon value. In the extremal limit, the Hawking temperature is shown to vanish. As with the scalar/tensor ...

Self-Completeness And Spontaneous Dimensional Reduction, 2017 Loyola Marymount University

#### Self-Completeness And Spontaneous Dimensional Reduction, Jonas R. Mureika, Piero Nicolini

##### Jonas Mureika

A viable quantum theory of gravity is one of the biggest challenges physicists are facing. We discuss the confluence of two highly expected features which might be instrumental in the quest of a finite and renormalizable quantum gravity —spontaneous dimensional reduction and self-completeness. The former suggests the spacetime background at the Planck scale may be effectively two-dimensional, while the latter implies a condition of maximal compression of matter by the formation of an event horizon for Planckian scattering. We generalize such a result to an arbitrary number of dimensions, and show that gravity in higher than four dimensions remains self-complete ...

2017 Loyola Marymount University

#### The Effects Of Temperature, Humidity, And Barometric Pressure On Short-Sprint Race Times, Jonas R. Mureika

##### Jonas Mureika

A numerical model of 100 m and 200 m world class sprinting performances is modified using standard hydrodynamic principles to include effects of air temperature, pressure, and humidity levels on aerodynamic drag. The magnitude of the effects are found to be dependent on wind speed. This implies that differing atmospheric conditions can yield slightly different corrections for the same wind gauge reading. In the absence of wind, temperature is found to induce the largest variation in times (0.01 s per 10◦C increment in the 100 m), while relative humidity contributes the least (under 0.01 s for all ...

Multifractal Structure In Nonrepresentational Art, 2017 Loyola Marymount University

#### Multifractal Structure In Nonrepresentational Art, Jonas R. Mureika, C. C. Dyer, G. C. Cupchik

##### Jonas Mureika

Multifractal analysis techniques are applied to patterns in several abstract expressionist artworks, painted by various artists. The analysis is carried out on two distinct types of structures: the physical patterns formed by a specific color (“blobs”) and patterns formed by the luminance gradient between adjacent colors (“edges”). It is found that the multifractal analysis method applied to “blobs” cannot distinguish between artists of the same movement, yielding a multifractal spectrum of dimensions between about 1.5 and 1.8. The method can distinguish between different types of images, however, as demonstrated by studying a radically different type of art. The ...

Does Entropic Gravity Bound The Masses Of The Photon And Graviton?, 2017 Loyola Marymount University

#### Does Entropic Gravity Bound The Masses Of The Photon And Graviton?, Jonas R. Mureika, R. B. Mann

##### Jonas Mureika

If the information transfer between test particle and holographic screen in entropic gravity respects both the uncertainty principle and causality, a lower limit on the number of bits in the universe relative to its mass may be derived. Furthermore, these limits indicate particles that putatively travel at the speed of light -- the photon and/or graviton -- have a non-zero mass m≥10−68 kg. This result is found to be in excellent agreement with current experimental mass bounds on the graviton and photon, suggesting that entropic gravity may be the result of a (recent) softly-broken local symmetry. Stronger bounds emerge ...

Self-Completeness And The Generalized Uncertainty Principle, 2017 Loyola Marymount University

#### Self-Completeness And The Generalized Uncertainty Principle, Maximiliano Isi, Jonas Mureika, Piero Nicolini

##### Jonas Mureika

The generalized uncertainty principle discloses a self-complete characteristic of gravity, namely the possibility of masking any curvature singularity behind an event horizon as a result of matter compression at the Planck scale. In this paper we extend the above reasoning in order to overcome some current limitations to the framework, including the absence of a consistent metric describing such Planck-scale black holes. We implement a minimum-size black hole in terms of the extremal configuration of a neutral non-rotating metric, which we derived by mimicking the effects of the generalized uncertainty principle via a short scale modified version of Einstein gravity ...

2017 Loyola Marymount University

#### Primordial Black Hole Evaporation And Spontaneous Dimensional Reduction, Jonas R. Mureika

##### Jonas Mureika

Several different approaches to quantum gravity suggest the effective dimension of spacetime reduces from four to two near the Planck scale. In light of such evidence, this Letter re-examines the thermodynamics of primordial black holes (PBHs) in specific lower-dimensional gravitational models. Unlike in four dimensions, (1 + 1)-D black holes radiate with power P ∼ M2BH, while it is known no (2+1)-D (BTZ) black holes can exist in a non-anti-de Sitter universe. This has important relevance to the PBH population size and distribution, and consequently on cosmological evolution scenarios. The number of PBHs that have evaporated to ...

Unparticle-Enhanced Black Holes At The Lhc, 2017 Loyola Marymount University

#### Unparticle-Enhanced Black Holes At The Lhc, Jonas R. Mureika

##### Jonas Mureika

Based on the idea that tensor unparticles can enhance the gravitational interactions between standard model particles, potential black hole formation in high energy collisions is examined. Modifications to the horizon radius rH are derived, and the corresponding geometric cross-sections of such objects are calculated. It is shown that rH increases dramatically to the electroweak scale for masses MBH∼1–10 TeV, yielding a geometric cross-section σBH=πr2H on the order of ⩽50 pb. This suggests that unparticle physics provides a mechanism for black hole formation in future accelerators, without the requirement of extra spatial dimensions.

2017 Loyola Marymount University

#### Gravitationally Induced Quantum Superposition Reduction With Large Extra Dimensions, Jonas R. Mureika

##### Jonas Mureika

A gravity-driven mechanism (objective reduction'') proposed to explain quantum state reduction is analyzed in light of the possible existence of large extra dimensions in the ADD scenario. By calculating order-of-magnitude estimates for nucleon superpositions, it is shown that if the mechanism at question is correct, constraints may be placed on the number and size of extra dimensions. Hence, measurement of superposition collapse times ({\it e.g.} through diffraction or reflection experiments) could represent a new probe of extra dimensions. The influence of a time-dependent gravitational constant on the gravity-driven collapse scheme with and without the presence of extra dimensions is ...