392 research outputs found
The Charles Potts Collection: Cataloging a Cultural Movement
No full textCounter-culture poet, activist, entrepreneur, and publisher, Charles Potts donated his personal poetry library and papers to Utah State University’s Special Collections and Archives in 2011 During his time at Berkeley, Potts\u27 describes himself as a ‘revolutionary hippie’ in the counter-culture poetry scene. Overall, this great American poet has spent nearly 50 years as an author of numerous books containing compilations of his postmodern poetry as well as full length novels and even a screenplay
Critical properties of quantum three- and four-state Potts models with boundaries polarized along the transverse field
No full textBy computing the low-lying energy excitation spectra with the density matrix
renormalization group algorithm we show that boundaries polarized in the
direction of the transverse field lead to scale-invariant conformal towers of
states at the critical point of the quantum four-state Potts model - a special
symmetric case of the Ashkin-Teller model. Furthermore, by direct comparison of
the excitation spectra we phenomenologically establish the duality between the
transverse-polarized and three-state-mixed boundary conditions at the
four-state Potts critical point. Finally, for completeness, we verify that in
the quantum three-state Potts model the "new" boundary conditions dual to the
mixed ones can be realized by polarizing edge spins along the transverse field.Comment: 19 pages, 7 figure
Proof of the determinantal form of the spontaneous magnetization of the superintegrable chiral Potts model
No full textThe superintegrable chiral Potts model has many resemblances to the Ising model, so it is natural to look for algebraic properties similar to those found for the Ising model by Onsager, Kaufman and Yang. The spontaneous magnetization can be written in terms of a sum over the elements of a matrix . The author conjectured the form of the elements, and this conjecture has been verified by Iorgov et al. The author also conjectured in 2008 that this sum could be expressed as a determinant, and has recently evaluated the determinant to obtain the known result for . Here we prove that the sum and the determinant are indeed identical expressions. Since the order parameters of the superintegrable chiral Potts model are also those of the more general solvable chiral Potts model, this completes the algebraic calculation of for the general model.
doi:10.1017/S144618111000078
Potts model clustering for discovering patterns of epigenetic marks
No full textStudy of epigenetics leads to understanding of the regulation of gene expression not caused by the changes in the underlying DNA sequences. This area of biological research has drawn much interest as large amounts of epigenetic data from numerous experiments were generated in recent past. In this thesis, we use the Potts model clustering method, which is based on statistical mechanics, to discover patterns in histone modification data. After a general overview of the epigenome and an introduction to common methods of clustering, we discuss why we need special cluster analysis methods for the data at hand. Then, we introduce our tool of choice, namely, the superparamagnetic Potts clustering method. We discuss the Potts model and the Swendsen-Wang method of Monte Carlo simulation, which avoids the usual slowing down experienced near phase transition. We apply Potts model clustering to histone modification data in highly conserved regions to discover the patterns of epigenetic marks and compare them with background reading. We also contrast the results from our method with that from usual Kmeans clustering approach. Finally, we discuss the biological significance of our computational results.Ph.D.Includes bibliographical referencesIncludes vitaby Junyi L
Pre-Islamic Iranian calendrical systems in the context of Iranian religious and scientific history
No full textThe author presents the calendrical systems used in Pre-Islamic Iran in the context of the Iranian religions and shows the development of the so-called "Zoroastrian calendar", with particular regard to the history of science
A Monte Carlo study of the three-states antiferromagnetic Potts model in two dimensions
No full textUsing Monte Carlo methods the author studies the two-dimensional three-stages Potts model with antiferromagnetic nearest neighbours and ferromagnetic next-nearest neighbours couplings on a square lattice. The author focuses on the case with only antiferromagnetic coupling; from the analysis of the data gathered, there is evidence that this system shows critical behaviour only at T=0
Identifying the Huse-Fisher universality class of the three-state chiral Potts model
No full textUsing the corner-transfer matrix renormalization group approach, we revisit the three-state chiral Potts model on the square lattice, a model proposed in the eighties to describe commensurate-incommensurate transitions at surfaces, and with direct relevance to recent experiments on chains of Rydberg atoms. This model was suggested by Huse and Fisher to have a chiral transition in the vicinity of the Potts point, a possibility that turned out to be very difficult to definitely establish or refute numerically. Our results confirm that the transition changes character at a Lifshitz point that separates a line of Pokrosky-Talapov transitions far enough from the Potts point from a line of direct continuous order-disorder transition close to it. Thanks to the accuracy of the numerical results, we have been able to base the analysis entirely on effective exponents to deal with the crossovers that have hampered previous numerical investigations. The emerging picture is that of a new universality class with exponents that do not change between the Potts point and the Lifshitz point, and that appear to be consistent with those of a self-dual version of the model, namely correlation lengths exponents v(x) = 2/3 in the direction of the asymmetry and v(y) = 1 perpendicular to it, an incommensurability exponent beta = 2/3, a specific heat exponent that keeps the value alpha = 1 /3 of the three-state Potts model, and a dynamical exponent z = 3/2. These results are in excellent agreement with experimental results obtained on reconstructed surfaces in the nineties, and shed light on recent Kibble-Zurek experiments on the period-3 phase of chains of Rydberg atoms. (C) 2021 The Author(s). Published by Elsevier B.V.CTM
Aspects of Kinship in Ancient Iran
No full textOriginally delivered in 2020 as the Biennial Ehsan Yarshater Lectures, Aspects of Kinship in Ancient Iran is an exploration of kinship in the archaeological and historical record of Iran’s most ancient civilizations. D. T. Potts brings together history, archaeology, and social anthropology to provide an overview of what we can know about the kith and kinship ties in Iran, from prehistory to Elamite, Achaemenid, and Sasanian times. In so doing, he sheds light on the rich body of evidence that exists for kin relations in Iran, a topic that has too often been ignored in the study of the ancient world.
“As always with this excellent authority on ancient Iranian history and cultures, D. T. Potts presents five highly innovative essays on forms of kinship and social organization in ancient Iran from the Elamites to the Sasanians that are full of new ideas and suggestions for further research.” — Josef Wiesehöfer, Professor Emeritus of Ancient History and Classics, University of Kiel, and author of Ancient Persia: From 550 BC to 650 A
Lynndyl School 4-6 grades
No full textTop to bottom: unknown, Craig Greathouse, Ila Mae Overson, Patricia Nielson, Paula Simpson, unknown, unknown, Teacher-LaForge Lovell, unknown, Jackee Nelson, Rick Simpson, Ann Nelson, George Johnson, Leona Potts, Delbert Carrington, Wendell Nelson, Arlene Dutson, unknown, Lynndyl, Uta
Aspects of Kinship in Ancient Iran
No full textOriginally delivered in 2020 as the Biennial Ehsan Yarshater Lectures, Aspects of Kinship in Ancient Iran is an exploration of kinship in the archaeological and historical record of Iran’s most ancient civilizations. D. T. Potts brings together history, archaeology, and social anthropology to provide an overview of what we can know about the kith and kinship ties in Iran, from prehistory to Elamite, Achaemenid, and Sasanian times. In so doing, he sheds light on the rich body of evidence that exists for kin relations in Iran, a topic that has too often been ignored in the study of the ancient world.
“As always with this excellent authority on ancient Iranian history and cultures, D. T. Potts presents five highly innovative essays on forms of kinship and social organization in ancient Iran from the Elamites to the Sasanians that are full of new ideas and suggestions for further research.” — Josef Wiesehöfer, Professor Emeritus of Ancient History and Classics, University of Kiel, and author of Ancient Persia: From 550 BC to 650 A
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