scholarly journals Computing the Sound of the Sea in a Seashell

2021 ◽  
Author(s):  
Jonathan Ben-Artzi ◽  
Marco Marletta ◽  
Frank Rösler
Keyword(s):  
Characteristic Function ◽  
Helmholtz Resonator ◽  
Positive Answer ◽  
Approximation Procedure ◽  
Universal Algorithm

AbstractThe question of whether there exists an approximation procedure to compute the resonances of any Helmholtz resonator, regardless of its particular shape, is addressed. A positive answer is given, and it is shown that all that one has to assume is that the resonator chamber is bounded and that its boundary is $${{\mathcal {C}}}^2$$ C 2 . The proof is constructive, providing a universal algorithm which only needs to access the values of the characteristic function of the chamber at any requested point.

Mars: was There an Ancient Eden?

1997 ◽  
Vol 161 ◽  
pp. 203-218 ◽  
Author(s):  
Tobias C. Owen
Keyword(s):  
Positive Answer ◽  
Biogenic Elements ◽  
Habitable Zones ◽  
The Face ◽  
The Origin Of Life ◽  
Early Mars ◽  
Favorable Conditions ◽  
Open Question ◽  
Rocky Planets ◽  
Impact Erosion

AbstractThe clear evidence of water erosion on the surface of Mars suggests an early climate much more clement than the present one. Using a model for the origin of inner planet atmospheres by icy planetesimal impact, it is possible to reconstruct the original volatile inventory on Mars, starting from the thin atmosphere we observe today. Evidence for cometary impact can be found in the present abundances and isotope ratios of gases in the atmosphere and in SNC meteorites. If we invoke impact erosion to account for the present excess of129Xe, we predict an early inventory equivalent to at least 7.5 bars of CO2. This reservoir of volatiles is adequate to produce a substantial greenhouse effect, provided there is some small addition of SO2(volcanoes) or reduced gases (cometary impact). Thus it seems likely that conditions on early Mars were suitable for the origin of life – biogenic elements and liquid water were present at favorable conditions of pressure and temperature. Whether life began on Mars remains an open question, receiving hints of a positive answer from recent work on one of the Martian meteorites. The implications for habitable zones around other stars include the need to have rocky planets with sufficient mass to preserve atmospheres in the face of intensive early bombardment.

Normative Concepts

2017 ◽  
Author(s):  
Matti Eklund
Keyword(s):  
Positive Answer ◽  
Thick Concepts ◽  
Normative Concepts ◽  
The Right ◽  
The Way

What is it for a concept to be normative? Some possible answers are explored and rejected, among them that a concept is normative if it ascribes a normative property. The positive answer defended is that a concept is normative if it is in the right way associated with a normative use. Among issues discussed along the way are the nature of analyticity, and there being a notion of analyticity—what I call semantic analyticity—such that a statement can be analytic in this sense while failing to be true. Considerations regarding thick concepts and slurs are brought to bear on the issues that come up.

Epilogue

2017 ◽  
Author(s):  
Robert Schütze
Keyword(s):  
Internal Market ◽  
Positive Answer ◽  
The Past ◽  
Output Legitimacy ◽  
The Eu

Can the judicial creation of the EU internal market be justified? A famous—positive—answer has, in the past, been suggested by Miguel Maduro’s We the Court; and the first section explores the credentials of his ‘majoritarian activism’ thesis. The second section surveys alternative forms of legitimacy, such as ‘output legitimacy’ and ‘messianic legitimacy’, but it also offers a new Kantian approach to the legitimacy question.

History, the Hindu Right, and Subversion of Brahmanical-Hindu Political Thought

2019 ◽  
pp. 239-260
Author(s):  
Stuart Gray
Keyword(s):  
Political Theory ◽  
Political Thought ◽  
Positive Answer ◽  
Source Material ◽  
Caste System ◽  
Hindu Tradition ◽  
Early Twenty ◽  
Indian Nationalism ◽  
Late Twentieth ◽  
Locus Classicus

How can scholars critically engage premodern Indic traditions without falling prey to Hindu conservatism or Brahmanical-Hindu apologism? This question is pressing for Indic political theory and contemporary Indian democracy because of ethnically exclusivist, Hindu nationalist movements that have emerged in the late twentieth and early twenty-first centuries. This chapter argues that a positive answer to the question must begin by taking seriously the tremendous pluralism in India’s political and philosophical history, which requires systematically engaging with premodern source material and uncovering the internal pluralism within a longer and larger Brahmanical-Hindu tradition of political thought. The author explains how it is both possible and politically necessary to internally subvert Brahmanical-Hindu political thought, which can help diffuse essentialist and exclusivist arguments coming from the Hindu right. Locating such plurality and engaging in internal subversion can help challenge historical justifications for Indian nationalism and contribute to decolonization, thus contesting the Hindu right on its own conceptual and genealogical turf. To advance this argument, the author provides a critical reinterpretation of the infamous “Puruṣa Sūkta,” which is often viewed as the locus classicus of the modern caste system, providing a novel interpretation that challenges caste hierarchy and supplies new resources for democratic thought and practice in India.

scholarly journals Non-negative Martingale Solutions to the Stochastic Thin-Film Equation with Nonlinear Gradient Noise

2021 ◽  
Author(s):  
Konstantinos Dareiotis ◽  
Benjamin Gess ◽  
Manuel V. Gnann ◽  
Günther Grün
Keyword(s):  
Thin Film ◽  
Energy Estimates ◽  
Approximation Procedure ◽  
Thin Film Flow ◽  
Thin Film Equations ◽  
Scalar Conservation Law ◽  
Thin Film Equation ◽  
Degenerate Parabolic ◽  
Scalar Conservation ◽  
Martingale Solutions

AbstractWe prove the existence of non-negative martingale solutions to a class of stochastic degenerate-parabolic fourth-order PDEs arising in surface-tension driven thin-film flow influenced by thermal noise. The construction applies to a range of mobilites including the cubic one which occurs under the assumption of a no-slip condition at the liquid-solid interface. Since their introduction more than 15 years ago, by Davidovitch, Moro, and Stone and by Grün, Mecke, and Rauscher, the existence of solutions to stochastic thin-film equations for cubic mobilities has been an open problem, even in the case of sufficiently regular noise. Our proof of global-in-time solutions relies on a careful combination of entropy and energy estimates in conjunction with a tailor-made approximation procedure to control the formation of shocks caused by the nonlinear stochastic scalar conservation law structure of the noise.

scholarly journals Pulsed characteristic-function measurement of a thermalizing harmonic oscillator

2021 ◽  
Vol 104 (1) ◽  
Author(s):  
Ralf Betzholz ◽  
Yu Liu ◽  
Jianming Cai
Keyword(s):  
Characteristic Function ◽  
Harmonic Oscillator ◽  
Function Measurement
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