1,485 research outputs found
From Koopman-von Neumann Theory to Quantum Theory
Koopman and von Neumann (KvN) extended the Liouville equation by introducing
a phase space function whose physical meaning is unknown. We
show that a different , with well-defined physical meaning, may be
introduced without destroying the attractive "quantum-like" mathematical
features of the KvN theory. This new is the classical action
expressed in phase space coordinates. It defines a mapping between observables
and operators which preserves the Lie bracket structure. The new evolution
equation reduces to Schr\"odinger's equation if functions on phase space are
reduced to functions on configuration space. This new kind of "quantization"
does not only establish a correspondence between observables and operators, but
provides in addition a derivation of quantum operators and evolution equations
from corresponding classical entities. It is performed by replacing
by and by , thus providing an explanation for the common
quantization rules.Comment: 7 pages, no figures, Quantum Stud.: Math. Found., 5(2), 219-22
Is the individuality interpretation of quantum theory wrong ?
We analyze the question whether or not quantum theory should be used to
describe single particles. Our final result is that a rational basis for such
an 'individuality interpretation' does not exist. A critical examination of
three principles, supporting the individuality interpretation, leads to the
result that no one of these principles seems to be realized in nature. The
well-known controversy characterized by the names of Einstein (EPR), Bohr and
Bell is analyzed. EPR proved 'predictive incompleteness' of quantum theory,
which implies that no individuality interpretation exists. Contrary to the
common opinion, Bell's proof of 'metaphysical completeness' does not invalidate
EPR's proof because two crucially different meanings of 'completeness' are
involved. The failure to distinguish between these two meanings is closely
related to a fundamentally deterministic world view, which dominated the
thinking of the 19th century and determines our thinking even today.Comment: 11 pages, no figure
Taboo, the Game: Patent Office Edition—The New Preissuance Submissions Under the America Invents Act
Thorough patent examination ensures that issued patents confer constitutionally granted incentives to innovate but do not create inappropriately broad monopolies. Examiners at the United States Patent and Trademark Office are alone tasked with striking this proper balance, in part by searching the universe of existing published knowledge to determine the originality of the applied-for invention.
In 2011, Congress enacted the Leahy-Smith America Invents Act, which included a provision allowing the public to present examiners with relevant publications that the examiners’ own searches might not otherwise uncover. However, this “preissuance submissions” provision and its related administrative rule are tempered by 35 U.S.C. § 122(c) (2006), which prohibits any third-party, pre-grant “protest or other form of [preissuance] opposition” to an application. Thus, although a party may describe to an examiner how its submission is relevant to an application, that party is prohibited from arguing how the submission renders that application unpatentable.
This Note argues that Congress should amend § 122(c) to permit preissuance third-party argumentation for two reasons. First, the current scheme arguably violates that law already. Second, a rule allowing submitter argumentation would better incentivize participation by competitive parties who fear that examiners might not recognize their submitted publications\u27 full invalidating potential
Regularization Methods for Nuclear Lattice Effective Field Theory
We investigate Nuclear Lattice Effective Field Theory for the two-body system
for several lattice spacings at lowest order in the pionless as well as in the
pionful theory. We discuss issues of regularizations and predictions for the
effective range expansion. In the pionless case, a simple Gaussian smearing
allows to demonstrate lattice spacing independence over a wide range of lattice
spacings. We show that regularization methods known from the continuum
formulation are necessary as well as feasible for the pionful approach.Comment: 7 pp, 2 figs, to appear in Physics Letters
Die Demethylierung von Dimethylselenid ist eine adaptive Antwort des Archaeons Methanococcus voltae
Im natürlichen Lebensraum von Methanococcus voltae
kommt Selen in unterschiedlichen Verbindungen und Konzentration
vor. So variiert der Selengehalt im Mündungswasser
verschiedener Flüsse zwischen 0,1 und 63 nM. Aufgrund der guten
Löslichkeit sind die Oxianionen des Selens biologisch am
interessantesten. Sie sind daher aber auch in hohen
Konzentrationen toxisch. Selen in geringen Mengen ist dagegen
essentiell, da es als Selenomethionin oder -cystein in
Proteinen vorkommen kann. Eine häufig anzutreffende organische
Selenverbindungen ist das Dimethylselenid (DMSe). Diese
flüchtige Substanz wird von einer Vielzahl Organismen zur
Detoxifizierung gebildet. Aus M. voltae sind insgesamt 4
Hydrogenasen bekannt, wovon zwei ein Selenocystein aufweisen
und konstitutiv exprimiert werden. Die Induktion der
Transkription der selenfreien Isoenzyme erfolgt dagegen bei
Selenmangel. In Expressionsanalysen zeigte sich, dass 5 weitere
Proteine ebenfalls nur unter Selenlimitierung synthetisiert
werden. Von zweien wurde jeweils die N-terminale Peptidsequenz
und von einem zusätzlich interne Peptidsequenzen bestimmt. In
der vorliegenden Arbeit wurde zunächst das Gen eines dieser
Proteine identifiziert. In einer Datenbanksuche stellte sich
dann heraus, dass es Sequenzidentitäten mit Corrinoid-Proteinen
aus Methanosarcina aufwies. Es wurde als SdmA bezeichnet (für
Dimethylselenid Demethylierung). Das Gen sdmA liegt zusammen
mit sdmB und sdmC auf einem gemeinsamen polycistronischen
Messenger, der nur bei Selenmangel nachweisbar war. SdmB und
SdmC haben gemeinsame Sequenzmotive mit Methyltransferasen, die
in einigen Methanoarchaeen an der methylotrophen Methanogenese
beteiligt sind. Dabei übertragen diese die Methylgruppe von
Corrinoid-Proteinen auf den Akzeptor Coenzym M. Die
Methylgruppe stammt dabei beispielsweise aus methylierten
Aminen bzw. Thiolen oder aus Methanol. Normalerweise werden von
M. voltae für die Methanogenese nur Formiat oder H2/CO2
erschlossen, so bestätigte sich die Vermutung nicht, dass bei
Selenmangel SdmA, SdmB und SdmC die Erschließung der oben
genannten methylierten Substrate erlauben könnten. Versetzt man
das Selenmangelmedium jedoch mit DMSe, dann führt dies zur
Repression des Promotors der Gene einer selenfreien
Hydrogenase, der normalerweise nur unter Selenlimitierung aktiv
wäre. Eine Deletion von sdmA oder sdmC führte zur Aktivität des
Promotors trotz der Anwesenheit von DMSe. Der Austausch von
sdmB hatte dagegen keinen Effekt. Zudem waren die
Wachstumsraten der Mutanten delta sdmA und delta sdmB im
Vergleich zum Wildtyp trotz DMSe-Zugabe reduziert. In M. voltae
scheint es daher zwei verschiedene Anpassungsmechanismen an
Selenmangel zu geben. Zum einen werden unter Selenlimitierung
die selenfreien Isoenzyme der selenhaltigen Hydrogenasen
exprimiert und zum anderen lässt sich unter diesen Bedingungen
ein alternatives Selensubstrat, wie das DMSe, von M. voltae zur
Biosynthese der Selenoproteine erschließen. Daran ist
vermutlich das Corrinoid-Proteine SdmA und die
Methyltransferase SdmC beteiligt
From probabilistic mechanics to quantum theory
We show that quantum theory (QT) is a substructure of classical probabilistic physics. The central quantity of the classical theory is Hamilton's function, which determines
canonical equations, a corresponding flow, and a Liouville equation for a probability density. We extend this theory in two respects: (1) The same structure is defined for arbitrary observables. Thus we have all of the above
entities generated not only by Hamilton's function but by every observable. (2) We introduce for each observable a
phase space function representing the classical action. This is a redundant quantity in a classical context but indispensable for the transition to QT. The basic equations of the resulting theory take a ``quantum-like'' form, which allows for a simple derivation of QT by means of a projection to configuration space reported previously [Quantum Stud.:Math. Found.(2018) 5:219-227]. We obtain the most important relations of QT, namely the form of operators, Schr\"odinger's equation, eigenvalue equations, commutation relations, expectation values, and Born's rule. Implications for the interpretation of QT are discussed, as well as an alternative projection method allowing for a derivation of spin
Lattice Improvement in Lattice Effective Field Theory
Lattice calculations using the framework of effective field theory have been
applied to a wide range few-body and many-body systems. One of the challenges
of these calculations is to remove systematic errors arising from the nonzero
lattice spacing. Fortunately, the lattice improvement program pioneered by
Symanzik provides a formalism for doing this. While lattice improvement has
already been utilized in lattice effective field theory calculations, the
effectiveness of the improvement program has not been systematically
benchmarked. In this work we use lattice improvement to remove lattice errors
for a one-dimensional system of bosons with zero-range interactions. We
construct the improved lattice action up to next-to-next-to-leading order and
verify that the remaining errors scale as the fourth power of the lattice
spacing for observables involving as many as five particles. Our results
provide a guide for increasing the accuracy of future calculations in lattice
effective field theory with improved lattice actions.Comment: 10 pages, 8 figure
- …