2,023 research outputs found
Wave equations with time-dependent dissipation II. Effective dissipation
No full textAbstractThis article is intended to present a construction of structural representations of solutions to the Cauchy problem for wave equations with time-dependent dissipation above scaling. These representations are used to give estimates of the solution and its derivatives based on Lq(Rn), q⩾2.The article represents the second part within a series. In [Jens Wirth, Wave equations with time-dependent dissipation I. Non-effective dissipation, J. Differential Equations 222 (2) (2006) 487–514] weak dissipations below scaling were discussed
Jens Christian Grøndahl
No full textThis is a short presentation of the main works of the Danish author Jens Christian Grøndahl
Jens August Schade
No full textShort presentation of Danish author Jens August Schade and his main work
Modulus of continuity and decay at infinity in evolution equations with real characteristics
No full textIn the hyperbolic Cauchy problem, the well-posedness in Sobolev
spaces and the modulus of continuity of the coefficients are deeply connected.
This holds true in the more general framework of p-evolution equations with
real characteristics
where a sharp
scale of Hoelder continuity, with respect to the time variable has
been established.
We show that, for p>1, a lack of regularity in t can be compensated by a
decay as the space variable x tends to infinit
A remark on the uniqueness for backward parabolic operators with non-Lipschitz-continuous coefficients
No full textUsing Bony's paramultiplication we improve a result obtained in [J. Math. Pures Appl. 84 (2005), no. 4, 471--491] for operators having coefficients non-Lipschitz-continuous with respect to but with respect to , showing that the same result is valid when is replaced by , with $\varepsilon>
Cm-theory of damped wave equations with stabilisation
No full textAbstractThe aim of this note is to extend the energy decay estimates from [J. Wirth, Wave equations with time-dependent-dissipation. I: Non-effective dissipation, J. Differential Equations 222 (2006) 487–514] to a broader class of time-dependent dissipation including very fast oscillations. This is achieved using stabilisation conditions on the coefficient in the spirit of [F. Hirosawa, On the asymptotic behavior of the energy for wave equations with time-depending coefficients, Math. Ann. 339 (4) (2007) 819–839]
Interview with Jens Zimmermann: Author of ‘Hermeneutics: A Very Short Introduction’
No full textDr. Jens Zimmermann is a German-Canadian philosopher and J.I. Packer Professor of Theology at Regent College. As the author of Hermeneutics: A Very Short Introduction, he held a lecture titled “Gadamer, Ricoeur and the Future of Philosophical Hermeneutics” at SFU. Hosted by the Department of World Languages and Literatures, the lecture focused on how we can use the art of hermeneutics to interpret literature and our identities of being human
On the Cauchy problem for hyperbolic operators with double characteristics
No full textThe aim of this work is to provide a survey, along with new recent results, of what is known about the C^infty well-posedness of the Cauchy problem for hyperbolic operators with doubel characteristics. Some conjectures and open problems will also be presented
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