Results for 'magnetic monopole'

936 found
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  1.  4
    Exact Magnetic Monopole Solutions in Yang-Mills and Unified Gauge Theories.J. P. Hsu - 1977 - Foundations of Physics 7 (11-12):801-812.
    We study the magnetic monopoles in non-Abelian gauge theories. The exact static, spherically symmetric solutions of the magnetic monopoles in both Yang-Mills and unified gauge theories are obtained. The energyE of the static system is calculable and it is either zero or infinite. The existence of the magnetic monopole solution is a consequence of symmetry rather than dynamics. We propose a new definition of the electromagnetic field tensor, which relates the static solution of gauge fields and (...)
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  2.  21
    Topological Quantization of the Magnetic Flux.Antonio F. Rañada & José Luis Trueba - 2006 - Foundations of Physics 36 (3):427-436.
    The quantization of the magnetic flux in superconducting rings is studied in the frame of a topological model of electromagnetism that gives a topological formulation of electric charge quantization. It turns out that the model also embodies a topological mechanism for the quantization of the magnetic flux with the same relation between the fundamental units of magnetic charge and flux as there is between the Dirac monopole and the fluxoid.
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  3.  12
    Magnetic Monopoles: Evidence Since the Dirac Conjecture. [REVIEW]Blas Cabrera & W. Peter Trower - 1983 - Foundations of Physics 13 (2):195-215.
    In the fifty-one years since its publication Dirac's magnetic monopole conjecture has stimulated a theoretical outpouring rich in variety. We review here the experimental techniques with which monopoles have been sought and we will describe the limits on monopole properties these searches have established.
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  4.  28
    Direct and Indirect Searches for Low-Mass Magnetic Monopoles.Leonard Gamberg, George R. Kalbfleisch & Kimball A. Milton - 2000 - Foundations of Physics 30 (4):543-565.
    Recently, there has been renewed interest in the search for low-mass magnetic monopoles. At the University of Oklahoma we are performing an experiment (Fermilab E882) using material from the old D0 and CDF detectors to set limits on the existence of Dirac monopoles of masses of the order of 500 GeV. To set such limits, estimates must be made of the production rate of such monopoles at the Tevatron collider, and of the binding strength of any such produced monopoles (...)
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  5.  22
    Duality in Off-Shell Electromagnetism.Martin Land - 2005 - Foundations of Physics 35 (7):1245-1262.
    In this paper, we examine the Dirac monopole in the framework of Off-Shell Electromagnetism, the five-dimensional U(1) gauge theory associated with Stueckelberg–Schrodinger relativistic quantum theory. After reviewing the Dirac model in four dimensions, we show that the structure of the five-dimensional theory prevents a natural generaliza tion of the Dirac monopole, since the theory is not symmetric under duality transforma tions. It is shown that the duality symmetry can be restored by generalizing the electromagnetic field strength to an (...)
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  6.  51
    Torsional Weyl-Dirac Electrodynamics.Mark Israelit - 1998 - Foundations of Physics 28 (2):205-229.
    Issuing from a geometry with nonmetricity and torsion we build up a generalized classical electrodynamics. This geometrically founded theory is coordinate covariant, as well as gauge covariant in the Weyl sense. Photons having arbitrary mass, intrinsic magnetic currents, (magnetic monopoles), and electric currents exist in this framework. The field equations, and the equations of motion of charged (either electrically or magnetically) particles are derived from an action principle. It is shown that the interaction between magnetic monopoles is (...)
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  7.  33
    Orbital and Field Angular Momentum in the Nucleon.D. Singleton & V. Dzhunushaliev - 2000 - Foundations of Physics 30 (7):1093-1105.
    The nucleon spin problem raises experimental and theoretical questions regarding the contribution of the orbital angular momentum of the quarks to the total spin of the nucleon. In this article we examine the commutation relationships of various operators that contribute to the total angular momentum of the nucleon. We find that the sum of the orbital plus gluon field angular momenta should satisfy the angular momentum commutators, at least up to the one-loop level. This, requirement on the sum of these (...)
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  8.  8
    A Minor or a Major Predicament of Physical Theory? (Charge and Action Polarity and Their Order Properties).E. J. Post - 1977 - Foundations of Physics 7 (3-4):255-277.
    The questions of observational error and ambiguity of interpretation that have been raised in connection with the reported observation of a magnetic monopole have precipitated a situation calling for some further insight into the pairing principles of nature. A basic distinction relates to whether or not a pair is “ordered” (e.g., sexual pair) or without a priori order (e.g., mirror pair). It is shown that the polarity of electric charge is to be regarded as an example of pairing (...)
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  9. Ethical Considerations in Functional Magnetic Resonance Imaging Research in Acutely Comatose Patients.Charles Weijer, Tommaso Bruni, Teneille Gofton, G. Bryan Young, Loretta Norton, Andrew Peterson & Adrian M. Owen - 2015 - Brain:0-0.
    After severe brain injury, one of the key challenges for medical doctors is to determine the patient’s prognosis. Who will do well? Who will not do well? Physicians need to know this, and families need to do this too, to address choices regarding the continuation of life supporting therapies. However, current prognostication methods are insufficient to provide a reliable prognosis. -/- Functional Magnetic Resonance Imaging (MRI) holds considerable promise for improving the accuracy of prognosis in acute brain injury patients. (...)
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  10.  30
    A Comparison of Masking by Visual and Transcranial Magnetic Stimulation: Implications for the Study of Conscious and Unconscious Visual Processing.Bruno G. Breitmeyer, Tony Ro & Haluk Ogmen - 2004 - Consciousness and Cognition 13 (4):829-843.
    Visual stimuli as well as transcranial magnetic stimulation can be used: to suppress the visibility of a target and to recover the visibility of a target that has been suppressed by another mask. Both types of stimulation thus provide useful methods for studying the microgenesis of object perception. We first review evidence of similarities between the processes by which a TMS mask and a visual mask can either suppress the visibility of targets or recover such suppressed visibility. However, we (...)
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  11.  8
    Effect of Repetitive Transcranial Magnetic Stimulation on Mood in Healthy Subjects.Virginie Moulier, Christian Gaudeau-Bosma, Clémence Isaac, Anne-Camille Allard, Noomane Bouaziz, Djedia Sidhoumi, Sonia Braha-Zeitoun, René Benadhira, Fanny Thomas & Dominique Januel - 2016 - Socioaffective Neuroscience and Psychology 6.
    BackgroundHigh frequency repetitive transcranial magnetic stimulation of the left dorsolateral prefrontal cortex has shown significant efficiency in the treatment of resistant depression. However in healthy subjects, the effects of rTMS remain unclear.ObjectiveOur aim was to determine the impact of 10 sessions of rTMS applied to the DLPFC on mood and emotion recognition in healthy subjects.DesignIn a randomised double-blind study, 20 subjects received 10 daily sessions of active or sham rTMS. The TMS coil was positioned on the left DLPFC through (...)
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  12.  6
    Nonlinear Models of Electric Charge and Magnetic Moment.I. Bersons & R. Veilande - 2015 - Foundations of Physics 45 (11):1526-1532.
    The models of the electric charge and magnetic moment are presented based on the nonlinear response of a vacuum on the applied electric and magnetic fields. The model of the electric charge contains one parameter—the radius of charge—and predicts one value of the electric charge for all elementary particles independently on the value of this radius. Different values of this parameter for the electron are discussed.
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  13. Using Functional Magnetic Resonance Imaging to Detect Covert Awareness in the Vegetative State.Adrian M. Owen, Martin R. Coleman, Melanie Boly, Matthew H. Davis, Steven Laureys & John D. Pickard - 2007 - Archives of Neurology 64 (8):1098-1102.
  14.  8
    Transcranial Magnetic Stimulation of the Human Frontal Eye Field Facilitates Visual Awareness.Marie-Hélène Grosbras & Tomáš Paus - 2003 - European Journal of Neuroscience 18 (11):3121-3126.
  15.  4
    Cells in the Non‐Uniform Magnetic World: How Cells Respond to High‐Gradient Magnetic Fields.Vitalii Zablotskii, Tatyana Polyakova & Alexandr Dejneka - 2018 - Bioessays 40 (8):1800017.
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  16. Models of Scientific Development and the Case of Nuclear Magnetic Resonance.Henk Zandvoort - 1986
     
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  17.  2
    Disruption of the Right Temporoparietal Junction with Transcranial Magnetic Stimulation Reduces the Role of Beliefs in Moral Judgments.Liane Young, Joan Albert Camprodon, Marc Hauser, Alvaro Pascual-Leone & Rebecca Saxe - 2010 - Proceedings of the National Academy of Sciences.
    When we judge an action as morally right or wrong, we rely on our capacity to infer the actor's mental states. Here, we test the hypothesis that the right temporoparietal junction, an area involved in mental state reasoning, is necessary for making moral judgments. In two experiments, we used transcranial magnetic stimulation to disrupt neural activity in the RTPJ transiently before moral judgment and during moral judgment. In both experiments, TMS to the RTPJ led participants to rely less on (...)
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  18. Mechanisms and Model-Based Functional Magnetic Resonance Imaging.Mark Povich - 2015 - Philosophy of Science 82 (5):1035-1046.
    Mechanistic explanations satisfy widely held norms of explanation: the ability to manipulate and answer counterfactual questions about the explanandum phenomenon. A currently debated issue is whether any nonmechanistic explanations can satisfy these explanatory norms. Weiskopf argues that the models of object recognition and categorization, JIM, SUSTAIN, and ALCOVE, are not mechanistic yet satisfy these norms of explanation. In this article I argue that these models are mechanism sketches. My argument applies recent research using model-based functional magnetic resonance imaging, a (...)
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  19.  19
    Anterior Cingulate Cortex-Related Connectivity in First-Episode Schizophrenia: A Spectral Dynamic Causal Modeling Study with Functional Magnetic Resonance Imaging.Long-Biao Cui, Jian Liu, Liu-Xian Wang, Chen Li, Yi-Bin Xi, Fan Guo, Hua-Ning Wang, Lin-Chuan Zhang, Wen-Ming Liu, Hong He, Ping Tian, Hong Yin & Hongbing Lu - 2015 - Frontiers in Human Neuroscience 9.
    Understanding the neural basis of schizophrenia (SZ) is important for shedding light on the neurobiological mechanisms underlying this mental disorder. Structural and functional alterations in the anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC), hippocampus, and medial prefrontal cortex (MPFC) have been implicated in the neurobiology of SZ. However, the effective connectivity among them in SZ remains unclear. The current study investigated how neuronal pathways involving these regions were affected in first-episode SZ using functional magnetic resonance imaging (fMRI). Forty-nine (...)
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  20.  16
    Transcranial Magnetic Stimulation of Early Visual Cortex Interferes with Subjective Visual Awareness and Objective Forced-Choice Performance.Mika Koivisto, Henry Railo & Niina Salminen-Vaparanta - 2011 - Consciousness and Cognition 20 (2):288-298.
    In order to study whether there exist a period of activity in the human early visual cortex that contributes exclusively to visual awareness, we applied transcranial magnetic stimulation over the early visual cortex and measured subjective visual awareness during visual forced-choice symbol or orientation discrimination tasks. TMS produced one dip in awareness 60–120 ms after stimulus onset, while forced-choice orientation discrimination was suppressed between 60 and 90 ms and symbol discrimination between 60 and 120 ms. Thus, a time window (...)
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  21. Classical Electromagnetic Interaction of a Point Charge and a Magnetic Moment: Considerations Related to the Aharonov–Bohm Phase Shift.Timothy H. Boyer - 2002 - Foundations of Physics 32 (1):1-39.
    A fundamentally new understanding of the classical electromagnetic interaction of a point charge and a magnetic dipole moment through order v 2 /c 2 is suggested. This relativistic analysis connects together hidden momentum in magnets, Solem's strange polarization of the classical hydrogen atom, and the Aharonov–Bohm phase shift. First we review the predictions following from the traditional particle-on-a-frictionless-rigid-ring model for a magnetic moment. This model, which is not relativistic to order v 2 /c 2 , does reveal a (...)
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  22.  39
    Transcranial Magnetic Stimulation: A Historical Evaluation and Future Prognosis of Therapeutically Relevant Ethical Concerns.Jared C. Horvath, Jennifer M. Perez, Lachlan Forrow, Felipe Fregni & Alvaro Pascual-Leone - 2011 - Journal of Medical Ethics 37 (3):137-143.
    Transcranial Magnetic Stimulation (TMS) is a non-invasive neurostimulatory and neuromodulatory technique increasingly used in clinical and research practices around the world. Historically, the ethical considerations guiding the therapeutic practice of TMS were largely concerned with aspects of subject safety in clinical trials. While safety remains of paramount importance, the recent US Food and Drug Administration approval of the Neuronetics NeuroStar TMS device for the treatment of specific medication-resistant depression has raised a number of additional ethical concerns, including marketing, off-label (...)
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  23.  74
    Remarks on the Magnetic Top.Akira Inomata, Georg Junker & Claudia Rosch - 1998 - Foundations of Physics 28 (5):729-739.
    We revisit via a path-integral approach the magnetic top proposed recently by Barut, Božić, and Marić. We point out that the magnetic top has the SU(2) symmetry and that it can be viewed as a free top seen from a rotating frame. We present an alternative path-integral quantization of the magnetic top on the basis of the symmetry, and show that the magnetic coupling does not participate in altering the spin quantum numbers.
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  24.  77
    Introducing Transcranial Magnetic Stimulation (TMS) and its Property of Causal Inference in Investigating Brain-Function Relationships.D. Schutter, J. van Honk & Jaak Panksepp - 2004 - Synthese 141 (2):155-73.
    Transcranial magnetic stimulation (TMS) is a method capable of transiently modulating neural excitability. Depending on the stimulation parameters information processing in the brain can be either enhanced or disrupted. This way the contribution of different brain areas involved in mental processes can be studied, allowing a functional decomposition of cognitive behavior both in the temporal and spatial domain, hence providing a functional resolution of brain/mind processes. The aim of the present paper is to argue that TMS with its ability (...)
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  25.  2
    Functional Magnetic Resonance Imaging, Covert Awareness, and Brain Iniury.Adrian M. Owen - 2011 - In Judy Illes & Barbara J. Sahakian (eds.), Oxford Handbook of Neuroethics. Oxford University Press. pp. 135.
    Rapid technological advances have produced a variety of novel techniques that allow a comprehensive assessment of brain function to be combined with detailed information about brain structure and connectivity. Any assessment that is based on exhibited behavior after brain injury will be prone to error for a number of reasons. These questions are explored in the context of recent studies in both healthy populations and brain injured patients that have sought to investigate covert awareness through the use of functional neuroimaging. (...)
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  26.  69
    On Hide's Magnetic Analogue of Ertel's Vorticity Theorem.Wilfried Schröder & Hans-Jürgen Treder - 1997 - Foundations of Physics 27 (10):1453-1455.
    The relativistic formulation of Hide's “magnetic analogue” of Ertel's potential vorticity theorem is Dirac's “new classical theory of electrons”.
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  27.  22
    The High Incidence and Bioethics of Findings on Magnetic Resonance Brain Imaging of Normal Volunteers for Neuroscience Research.N. Hoggard, G. Darwent, D. Capener, I. D. Wilkinson & P. D. Griffiths - 2009 - Journal of Medical Ethics 35 (3):194-199.
    Background: We were finding volunteers for functional magnetic resonance imaging studies with abnormalities requiring referral surprisingly frequently. The bioethics surrounding the incidental findings are not straightforward and every imaging institution will encounter this situation in their normal volunteers. Yet the implications for the individuals involved may be profound. Should all participants have review of their imaging by an expert and who should be informed? Methods: The normal volunteers that were imaged with magnetic resonance (MR) which were reviewed by (...)
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  28.  3
    ‘A Treasure Of Hidden Vertues’: The Attraction of Magnetic Marketing.Patricia Fara - 1995 - British Journal for the History of Science 28 (1):5-35.
    When customers like Samuel Pepys visited the shop of Thomas Tuttell, instrument maker to the king, they could purchase a pack of mathematical playing-cards. The seven of spades, reproduced as Figure 1, depicted the diverse connotations of magnets, or loadstones. These cards cost a shilling, and were too expensive for many of the surveyors, navigators and other practitioners shown using Tuttell's instruments. They provide an early example of the products promising both diversion and improvement which were increasingly marketed to polite (...)
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  29.  64
    Direct Observation of Magnetic Vortices in Superconductors Using Electron Waves.Akira Tonomura - 1998 - Foundations of Physics 28 (1):59-86.
    The development of a coherent field-emission electron beam has made it possible to observe microscopic magnetic lines of force by detecting the electron-wave phase shifts that are due to vector potentials. Electron-holographic interference microscopy has been used to observe magnetic lines of force of magnetic vortices in superconductors, and Lorentz microscopy has been used to observe the dynamics of the vortices. The observation of vortices not only helps us understand the microscopic mechanism of flux pinning, which holds (...)
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  30.  3
    Debates Over Magnetic Resonance Imaging in Mental Health Evaluations at Guantánamo.Neil Krishan Aggarwal - 2018 - Neuroethics 11 (3):337-346.
    Ethical debates over the use of mental health knowledge and practice at the Guantánamo Bay detention facility have mostly revolved around military clinicians sharing detainee medical information with interrogators, falsifying death certificates in interrogations, and disagreements over whether the Central Intelligence Agency’s “enhanced interrogation techniques” violated bioethical principles to do no harm. However, debates over the use of magnetic resonance imaging in the mental health evaluations of detainees have received little attention. This paper provides the first known analysis of (...)
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  31.  6
    Mechanizing Magnetism in Restoration England—the Decline of Magnetic Philosophy.Stephen Pumfrey - 1987 - Annals of Science 44 (1):1-21.
    The magnet served three interests of Restoration mechanical philosophers: it provided a model of cosmic forces, it suggested a solution to the problem of longitude determination, and evidence of its corpuscular mechanism would silence critics. An implicit condition of William Gilbert's ‘magnetic philosophy’ was the existence of a unique, immaterial magnetic virtue. Restoration mechanical philosophers, while claiming descent from their compatriot, worked successfully to disprove this, following an experimental regime of Henry Power. Magnetic philosophy lost its coherence (...)
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  32.  51
    The Magnetic Fields and Rotation Generators of Free Space Electromagnetism.M. W. Evans - 1994 - Foundations of Physics 24 (11):1519-1542.
    The relation is developed between rotation generators of the Lorentz group and the magnetic fields of free-space electromagnetism. Using these classical relations, it is shown that in the quantum field theory there exists a longitudinal photomagneton, a quantized magnetic flux density operator which is directly proportional to the photon spin angular momentum. Commutation relations are given in the quantum field between the longitudinal photomagneton and the usual transverse magnetic components of quantized electromagnetism. The longitudinal component is phase (...)
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  33.  5
    Incidental Findings in Magnetic Resonance Imaging (MRI) Brain Research.Charles A. Nelson - 2008 - Journal of Law, Medicine and Ethics 36 (2):315-319.
    The use of magnetic resonance imaging to investigate brain structure and function has become increasingly common among neuroscientists, psychologists, and even economists in recent years. Yet, despite this increase in use, relatively little attention has been paid to the issue of incidental fndings. The current paper discusses these issues, and anticipates the future of incidental fndings in the context of other neuroimaging tools currently being used to investigate the living brain.
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  34.  7
    Introducing Transcranial Magnetic Stimulation (TMS) and Its Property of Causal Inference in Investigating Brain-Function Relationships.Dennis J. L. G. Schutter, Jack Van Honk & Jaak Panksepp - 2004 - Synthese 141 (2):155 - 173.
    Transcranial magnetic stimulation (TMS) is a method capable of transiently modulating neural excitability. Depending on the stimulation parameters information processing in the brain can be either enhanced or disrupted. This way the contribution of different brain areas involved in mental processes can be studied, allowing a functional decomposition of cognitive behavior both in the temporal and spatial domain, hence providing a functional resolution of brain/mind processes. The aim of the present paper is to argue that TMS with its ability (...)
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  35.  13
    Molecular Beam Measurements of Nuclear Moments Before Magnetic Resonance. Part I: I. I. Rabi and Deflecting Magnets to 1938. [REVIEW]Paul Forman - 1998 - Annals of Science 55 (2):111-160.
    Investigation of the origin and function of three magnets from I. I. Rabi's laboratory at Columbia University leads to a closer inquiry into the early history of molecular beam evaluations of the angular momenta and magnetic moments of atomic nuclei than has been undertaken heretofore. The resulting insights into the background and the course of Rabi's research programme would probably not have occurred without the orientation enforced by these artifacts.
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  36.  39
    Vacuum Condensates and the Anomalous Magnetic Moment of a Dirac Fermion.Victor Elias, Kevin B. Sprague & Ying Xue - 2000 - Foundations of Physics 30 (3):439-461.
    We address anticipated fermion–antifermion and dimension-4 gauge-field vacuum-condensate contributions to the magnetic portion of the fermion–photon vertex function in the presence of a vacuum with nonperturbative content, such as that of QCD. We discuss how inclusion of such condensate contributions may lead to a vanishing anomalous magnetic moment, in which case vacuum condensates may account for the apparent consistency between constituent quark masses characterizing baryon magnetic moments and those characterizing baryon spectroscopy.
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  37.  4
    Fitting Geomagnetic Fields Before the Invention of Least Squares: I. Henry Bond's Predictions of the Change in Magnetic Declination in London. [REVIEW]Richard J. Howarth - 2002 - Annals of Science 59 (4):391-408.
    The London mathematical practitioner Henry Bond correctly forecast in The Sea-Mans Kalendar for 1636 [?1638] that the then easterly magnetic declination in London would become zero in 1657 and would then increase westerly for 'at least 30 years'. In 1668, he published a table of predicted changes in annual declination for the years 1668-1716. Despite a detailed examination of his later claim to be able to determine longitude using a dip needle, the basis for his earlier forecasts was not (...)
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  38.  32
    Physical Gauge in the Problem of Dynamical Chiral Symmetry Breaking in QED in a Magnetic Field.V. P. Gusynin, V. A. Miransky & I. A. Shovkovy - 2000 - Foundations of Physics 30 (3):349-357.
    We describe how the choice of an appropriate (“physical”) gauge leads to the solution of a nonperturbative problem in quantum electrodynamics: dynamical chiral symmetry breaking in QED in a constant magnetic field.
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  39.  23
    1 H Magnetic Resonance Spectroscopy of Normal Appearing White Matter in Primary Progressive Multiple Sclerosis.Siobhan M. Leary, Charles A. Davie, Geoff J. M. Parker, Valerie L. Stevenson, Liqun Wang, Gareth J. Barker, David H. Miller & A. J. Thompson - 1999 - Journal of Neurology 246 (11).
    Recent magnetic resonance imaging and pathological studies have indicated that axonal loss is a major contributor to disease progression in multiple sclerosis. 1 H magnetic resonance spectroscopy, through measurement of N -acetyl aspartate, a neuronal marker, provides a unique tool to investigate this. Patients with primary progressive multiple sclerosis have few lesions on conventional MRI, suggesting that changes in normal appearing white matter, such as axonal loss, may be particularly relevant to disease progression in this group. To test (...)
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  40.  30
    Zitterbewegung in External Magnetic Field: Classic Versus Quantum Approach. [REVIEW]Mehran Zahiri-Abyaneh & Mehrdad Farhoudi - 2011 - Foundations of Physics 41 (8):1355-1374.
    We investigate variations of the Zitterbewegung frequency of electron due to an external static and uniform magnetic field employing the expectation value quantum approach, and compare our results with the classical model of spinning particles. We demonstrate that these two so far compatible approaches are not in agreement in the presence of an external uniform static magnetic field, in which the classical approach breaks the usual symmetry of free particles and antiparticles states, i.e. it leads to CP violation. (...)
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  41.  37
    The Lie of Fmri: An Examination of the Ethics of a Market in Lie Detection Using Functional Magnetic Resonance Imaging. [REVIEW]Amy E. White - 2010 - HEC Forum 22 (3):253-266.
    In this paper, I argue that companies who use functional Magnetic Resonance Imaging (fMRI) scans for lie detection encounter the same basic ethical stumbling blocks as commercial companies that market traditional polygraphs. Markets in traditional voluntary polygraphs are common and fail to elicit much uproar among ethicists. Thus, for consistency, if markets in polygraphs are ethically unproblematic, markets using fMRIs for lie detection are equally as acceptable. Furthermore, while I acknowledge two substantial differences between the ethical concerns involving polygraphs (...)
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  42.  29
    Behavior of a Magnetic Dipole Freely Floating on Water Surface.M. A. & H. Kh - manuscript
    In this paper, the authors have detected a new effect in the area of geomagnetism, related to the behavior of a magnetic dipole freely floating on water surface. An experiment is described in the present paper in which a magnetic dipole fixed upon a float placed on non- magnetized water surface undergoes displacement along with reorientation caused by fine structure of the earth's magnetic field. This fact can probably be explained by secular decrease of the earth's major (...)
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  43.  18
    The Averaged Dynamics of the Hydrogen Atom in Crossed Electric and Magnetic Fields as a Perturbed Kepler Problem.Nils Berglund & Turgay Uzer - 2001 - Foundations of Physics 31 (2):283-326.
    We treat the classical dynamics of the hydrogen atom in perpendicular electric and magnetic fields as a celestial mechanics problem. By expressing the Hamiltonian in appropriate action–angle variables, we separate the different time scales of the motion. The method of averaging then allows us to reduce the system to two degrees of freedom, and to classify the most important periodic orbits.
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  44.  18
    Field Theory onR×S 3 Topology. IV: Electrodynamics of Magnetic Moments. [REVIEW]M. Carmeli & S. Malin - 1986 - Foundations of Physics 16 (8):791-806.
    The equations of electrodynamics for the interactions between magnetic moments are written on R×S3 topology rather than on Minkowskian space-time manifold of ordinary Maxwell's equations. The new field equations are an extension of the previously obtained Klein-Gordon-type, Schrödinger-type, Weyl-type, and Dirac-type equations. The concept of the magnetic moment in our case takes over that of the charge in ordinary electrodynamics as the fundamental entity. The new equations have R×S3 invariance as compared to the Lorentz invariance of Maxwell's equations. (...)
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  45.  1
    ‘O Tempera, O Magnes!’: A Sociological Analysis of the Discovery of Secular Magnetic Variation in 1634.Stephen Pumfrey - 1989 - British Journal for the History of Science 22 (2):181-214.
    As sociologists learn more about how scientific knowledge is created, they give historians the opportunity to rework their accounts from a more contextual perspective. It is relatively easy to do so in areas with large theoretical, cosmological or overtly ideological components. It is more difficult, but equally necessary, to open up very empirical accomplishments, and recent sociological analysis of the process of science gives us some interesting insights. This paper employs some of these on the apparently unpromising subject of the (...)
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  46.  15
    Bancalari's Role in Faraday's Discovery of Diamagnetism and the Successive Progress in the Understanding of Magnetic Properties of Matter.Giovanni Boato & Natalia Moro - 1994 - Annals of Science 51 (4):391-412.
    The events and thoughts which brought Michael Faraday to the discovery of diamagnetism in the year 1845 are reviewed and commented. The contribution of Bancalari, namely the discovery of diamagnetism in flame and gases made at the University of Genoa in 1847, had a strong impact on the continuation of Faraday's brilliant researches on magnetism in matter. Diamagnetism was carefully studied by him and other authors, while paramagnetism was revealed in solid, liquid, and gaseous substances. A systematic study of the (...)
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  47.  17
    Bound States of the Nucleon-Monopole System.Tetsuo Sawada - 1993 - Foundations of Physics 23 (2):291-311.
    The energy spectrum of the bound states of the nucleon-monopole system is determined, the monopole harmonics Yq,l,m are related to Wigner's functions D m,m′ (L) of the rotation matrix, and the scattering wave functions of the proton in the dyon source field are calculated.
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  48.  14
    Exact Solutions of the Duffin-Kemmer-Petiau Equation with a Pseudoharmonic Potential in the Presence of a Magnetic Field in (1+2) Dimensions. [REVIEW]H. Hassanabadi, Z. Molaee & A. Boumali - 2013 - Foundations of Physics 43 (2):225-235.
    We will consider the relativistic Duffin-Kemmer-Petiau equation in the presence of a pseudoharmonic potential in a magnetic field in the (1+2)-dimensional space-time for spin-one particles. To derive the energy eigenvalues and corresponding eigenfunctions, the analytical Nikiforov-Uvarov Method is used and some explanatory figures are included.
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  49.  12
    On Magnetic Moment and Magnetic Induction.N. D. Sen Gupta - 1976 - Foundations of Physics 6 (4):401-405.
    An attempt is made to introduce the concept of magnetic moment and magnetic induction directly from observed mechanical interactions between magnets, without bringing in the idealized notion of isolated magnetic poles.
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  50.  11
    Magnetic Symmetry, Improper Symmetry, and Neumann's Principle.E. J. Post - 1978 - Foundations of Physics 8 (3-4):277-294.
    Mathematical tradition has it that transformations characterized by a negative Jacobian determinant are referred to as improper transformations. The symmetry of a physical object corresponding to such an improper transformation becomes an improper symmetry. Improper symmetries have been successfully used for the purpose of crystal symmetry. The extension of these purely spatial symmetries to the domain of spacetime has led to a prejudicial use of light-cone properties, thus affecting adversely an unbiased symmetry classification. We pinpoint these prejudicial procedures and trace (...)
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