Shourrya Ray et équation de Newton

[invitee2d9a777]

Bonjour,

Je ne trouve rien sur futura science sur Shourrya Ray.

Une raison ?

Quelqu'un connait-il l'équation dont il est question ?

Cordialement.
-----

[phys4]

Bonjour,

Cela semble une très belle opération de pub.

Les deux exemples cités par les journaux sont des problèmes bien connus et résolus depuis longtemps, il est vrai à un niveau mathématique assez sérieux.
Vous trouverez les solutions dans Futura sans grande difficulté.

[invitee2d9a777]

Je me disais aussi ...

Merci.

[Amanuensis]

Pas vraiment un coup de pub, il s'agit d'un prix pour jeunes, et c'est en Allemagne. Ce sont les journalistes qui ont "amplifié" et déformé le sujet.

Je copie une réponse trouvée sur http://math.stackexchange.com/questi...e-is-the-paper (en anglais, mais les équations se comprennent dans toutes les langues...)

------

Conducting an internship at the Chair of Fluid Mechanics at TU Dresden, Shouryya Ray encountered two ordinary differential equations which are special cases of Newton's law that the derivative of the momentum of a particle equals the forces acting on it. In the first one, which describes the motion of a particle in a gas or fluid, this force is the sum of a damping force, which depends quadratically on the velocity, and the (constant) gravitational force.



Here, u and v are the horizontal and vertical velocity, respectively.

(...)

The second equation reads



and describes the trajectory of the center point z(t) of a spherical particle during a normal collision with a plane wall. (...)

Let us come back to problem (1) which was the starting point of the media stories. In the context of Shouryya Ray's work it was an unfortunate circumstance, that a recent article from 2007 claims that no analytical solution of problem (1) was known, or that it was known only in special cases, namely falling objects. This might have misled Shouryya Ray who was not aware of the classical theory of ordinary differential equations. (...)

To conclude, Shouryya Ray has obtained analytic solutions of the problem (1), by transforming it successively to the problems (3)-(5), and by applying a recent result of D. Dominici in order to obtain a recursive formula for the coefficients of the power series representation of . He then validated his results numerically. Given the level of prerequisites that he had, he made great progress. Nevertheless all his steps are basically known to experts and we emphasize that he did not solve an open problem posed by Newton. (...)

We hope that this small text gives the necessary information to the mathematical community, and that it allows the community to both put in context and appreciate the work of Shouryya Ray who plans to start a career in mathematics and physics.

[A voir en vidéo sur Futura]

[inviteea028771]

Ce sont les journalistes qui ont "amplifié" et déformé le sujet.

Comme c'est étonnant