7,013 research outputs found
N=2 supersymmetric odd-order Pais–Uhlenbeck oscillator
No full textWe consider an N=2 supersymmetric odd-order Pais–Uhlenbeck oscillator with distinct frequencies of oscillation. The technique previously developed in [Bolonek and Kosinski (2005) [7]], [Masterov (2016) [10]] is used to construct a family of Hamiltonian structures for this system
Dynamical realizations of l-conformal Newton–Hooke group
No full textAbstractThe method of nonlinear realizations and the technique previously developed in [A. Galajinsky, I. Masterov, Nucl. Phys. B 866 (2013) 212, arXiv:1208.1403] are used to construct a dynamical system without higher derivative terms, which holds invariant under the l-conformal Newton–Hooke group. A configuration space of the model involves coordinates, which parametrize a particle moving in d spatial dimensions and a conformal mode, which gives rise to an effective external field. The dynamical system describes a generalized multi-dimensional oscillator, which undergoes accelerated/decelerated motion in an ellipse in accord with evolution of the conformal mode. Higher derivative formulations are discussed as well. It is demonstrated that the multi-dimensional Pais–Uhlenbeck oscillator enjoys the l=32-conformal Newton–Hooke symmetry for a particular choice of its frequencies
An alternative Hamiltonian formulation for the Pais–Uhlenbeck oscillator
No full textAbstractOstrogradsky's method allows one to construct Hamiltonian formulation for a higher derivative system. An application of this approach to the Pais–Uhlenbeck oscillator yields the Hamiltonian which is unbounded from below. This leads to the ghost problem in quantum theory. In order to avoid this nasty feature, the technique previously developed in [7] is used to construct an alternative Hamiltonian formulation for the multidimensional Pais–Uhlenbeck oscillator of arbitrary even order with distinct frequencies of oscillation. This construction is also generalized to the case of an N=2 supersymmetric Pais–Uhlenbeck oscillator
On dynamical realizations of l-conformal Galilei and Newton–Hooke algebras
No full textIn two recent papers (Aizawa et al., 2013 [15]) and (Aizawa et al., 2015 [16]), representation theory ofthe centrally extended l-conformal Galilei algebra with half-integer l has been applied so as to constructsecond order differential equations exhibiting the corresponding group as kinematical symmetry. It wassuggested to treat them as the Schrodinger equations which involve Hamiltonians describing dynamicalsystems without higher derivatives. The Hamiltonians possess two unusual features, however. First, theyinvolve the standard kinetic term only for one degree of freedom, while the remaining variables providecontributions linear in momenta. This is typical for Ostrogradsky’s canonical approach to the description ofhigher derivative systems. Second, the Hamiltonian in the second paper is not Hermitian in the conventionalsense. In this work, we study the classical limit of the quantum Hamiltonians and demonstrate that the firstof them is equivalent to the Hamiltonian describing free higher derivative nonrelativistic particles, whilethe second can be linked to the Pais–Uhlenbeck oscillator whose frequencies form the arithmetic sequence?k = (2k ? 1), k = 1,..., n. We also confront the higher derivative models with a genuine second ordersystem constructed in our recent work (Galajinsky and Masterov, 2013 [5]) which is discussed in detailfor l = 32
Yuriy Hryvniak as a researcher of the biography of Ivan Puluj
No full textМатеріал тез присвячено дослідженню сторінок біографії
Юрія Гривняка - автора монографії про Івана Пулюя, яку було
опубліковано 1971 року у Лондоні завдяки фінансовій підтримці Союзу
українців у Великій Британії. Автором було використано ряд фото та
архівних матеріалів, отриманих від О. Пулюя. На жаль, творчість і
життєвий шлях Ю. Гривняка є маловідомими в Україні, а доля зібраних
ним джерел потребує фахового дослідженняThese theses are devoted to the study of the pages of Yuriy
Hryvniak’s biography. He was the author of a monograph dedicated to the study
of the life and activities of the famous Ukrainian scientist and public figure Ivan
Puluj. The author used a number of photos and archival materials received from
O. Puluj. Unfortunately, the creativity and life path of Y. Hryvniak is little
known in Ukraine, and the fate of the sources collected by him requires
professional researc
Note from David Kirchman to Ivan Valiela at the Ecosystems Center
No full textTitle page of the book "Processes in Microbal Ecology". The author, David L. Kirchman, has written a note to Ecosystems Center scientist Ivan Valiela.Note reads: "Ivan- You & the MBL Marine Ecology course got me going in this field. Thanks. David Kirchman"photograph
Ivan Žuvela Šabo and His Etnographic Record from 1892
No full textU ovom tekstu otkriva se identitet autora jednog starijeg etnografskog zapisa nastalog na otoku Korčuli. Riječ je o rukopisu „Narodne pjesme junačke i žetelačke“ iz 1892., a koji se čuva u Arhivu Odsjeka za etnologiju Hrvatske akademije znanosti i umjetnosti u Zagrebu. Iako je u tom rukopisu autor potpisan kao „Ivan Žuvela, pravnik“, dosada ga se nije moglo točnije identificirati, iznesena je kriva pretpostavka, a čak se i spekuliralo da je riječ o pseudonimu. Istraživanjem dostupnih izvora i novinskih zapisa ipak se utvrdilo kako je zaista riječ o Velolučaninu Ivanu Žuveli iz grane Šabo, studentu prava koji je umro u svojoj 23-oj godini života, samo godinu dana po nastanku ovog rukopisa. Uz autora, u tekstu se detaljno progovara o rukopisu i njegovom iznimnom značaju za proučavanje nekadašnje svakodnevice, a posebno žetelačkih običaja na zapadnom dijelu otoka Korčule.This text reveals the identity of the hitherto unknown author one of the oldest known ethnographic record from the island of Korčula. The manuscript titled “Narodne pjesme junačke i žetelačke” (Folk Songs of Heroes and Harvesters) dates back to 1892 and is preserved in the Archive of the Ethnology Division at the Croatian Academy of Sciences and Arts in Zagreb. Although the author of the manuscript is signed as “Ivan Žuvela, legal scholar,” his precise identification has remained elusive, with incorrect assumptions and even speculation about a possible pseudonym. Through research of available sources and newspaper records, it has now been conclusively determined that the author is indeed Ivan Žuvela from Vela Luka, a member of the Šabo family, and a law student who passed away at the age of 23, just a year after creating this manuscript. In addition to introducing the author, this text provides a detailed exploration of the manuscript and its exceptional significance for studying the everyday life of the past, particularly the harvesting customs on the western part of the island of Korčula
Riflessioni su "Note su una teoria d'impresa" di Ivan Snehota
No full textIl capitolo ripercorre, riassume e discute i lavori scientifici del prof. Ivan Snehota a partire dalla monografia "Note su una teoria d'impresa" che contiene le basi del suo pensiero e del futuro lavoro di ricerca. Traendo spunto dagli studi del prof. Snehota l'Autore suggerisce percorsi di sviluppo della ricerca sulle reti tra imprese.The chapter summarizes and debates Emeritus prof. Ivan Snehota's studies since his Ph.D thesis. Following such an analysis the author suggests future research directions on the topic of business networks
The odd-order Pais–Uhlenbeck oscillator
No full textAbstractWe consider a Hamiltonian formulation of the (2n+1)-order generalization of the Pais–Uhlenbeck oscillator with distinct frequencies of oscillation. This system is invariant under time translations. However, the corresponding Noether integral of motion is unbounded from below and can be presented as a direct sum of 2n one-dimensional harmonic oscillators with an alternating sign. If this integral of motion plays a role of a Hamiltonian, a quantum theory of the Pais–Uhlenbeck oscillator faces a ghost problem. We construct an alternative canonical formulation for the system under study to avoid this nasty feature
Towards an Augmented Reality Game for Learning about Ivan Vazov's Literary Works
No full textThis paper presents a concept for a serious game based on an augmented reality representation of a mural artwork located in the National Library
“Ivan Vazov” in Plovdiv, Bulgaria. The mural features the renowned Bulgarian author Ivan Vazov in the center, surrounded by characters from his literary works.
By using a head-mounted display in front of the mural, the players would see movement of the characters and will be able to interact with them in a gamified augmented reality environment. The serious game proposed in this paper offers a solution to the engagement of players with literature and textual heritage within a broader cultural context
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