Publication
Some Notes About the Fermi-Pasta-Ulam Problem
| dc.contributor.author | Tenreiro Machado, J. A. | |
| dc.date.accessioned | 2019-04-16T10:38:04Z | |
| dc.date.available | 2019-04-16T10:38:04Z | |
| dc.date.issued | 2011-11 | |
| dc.description.abstract | During 1953, at Los Alamos, Fermi, Pasta and Ulam (FPU) developed computer simulations of a mechanical system composed of masses and springs [1]. We should also refer Mary Tsingou that helped in the programming of the computer Maniac. The idea formulated by Enrico Fermi was to simulate the one-dimensional analogue of atoms in a crystal by mean of a chain of particles linked by springs fixed at the extreme points. The springs were modeled by a term following a linear model (Hooke’s law) and a nonlinear term either quadratic (FPU -α), or cubic (FPU -β). These researchers found a dynamics considerably different from what linear systems would suggest. In fact, they thought that the system would exhibit “thermalization”, that is, a behavior in which the influence of the initial modes of vibration would fade, becoming all modes excited equally. Nevertheless, the simulations revealed a complex quasi-periodic dynamics. They thought that the energy introduced into the first frequency mode (k = 1) should drift to the other modes until the equipartition of energy would be reached. For the first instants of the simulation the higher modes (k = 2, 3,…) were successively excited, reaching almost an equipartition state, but after some time they verified that almost all energy was back to the first mode. Further simulations revealed the repetition of this phenomenon and that a kind of recurrence emerges, being recovered replicas of the initial state [2-4]. | pt_PT |
| dc.description.version | N/A | pt_PT |
| dc.identifier.uri | http://hdl.handle.net/10400.22/13582 | |
| dc.language.iso | eng | pt_PT |
| dc.title | Some Notes About the Fermi-Pasta-Ulam Problem | pt_PT |
| dc.type | conference object | |
| dspace.entity.type | Publication | |
| oaire.citation.conferencePlace | Coimbra, Portugal | pt_PT |
| oaire.citation.endPage | 25 | pt_PT |
| oaire.citation.startPage | 21 | pt_PT |
| oaire.citation.title | Symposium On Fractional Signals and Systems | pt_PT |
| person.familyName | Tenreiro Machado | |
| person.givenName | J. A. | |
| person.identifier.ciencia-id | 7A18-4935-5B29 | |
| person.identifier.orcid | 0000-0003-4274-4879 | |
| person.identifier.rid | M-2173-2013 | |
| person.identifier.scopus-author-id | 55989030100 | |
| rcaap.rights | openAccess | pt_PT |
| rcaap.type | conferenceObject | pt_PT |
| relation.isAuthorOfPublication | 82cd5c17-07b6-492b-b3e3-ecebdad1254f | |
| relation.isAuthorOfPublication.latestForDiscovery | 82cd5c17-07b6-492b-b3e3-ecebdad1254f |