1,782 research outputs found

    Planckian Axions in String Theory

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    We argue that super-Planckian diameters of axion fundamental domains can naturally arise in Calabi-Yau compactifications of string theory. In a theory with NN axions θi\theta^i, the fundamental domain is a polytope defined by the periodicities of the axions, via constraints of the form −π<Qjiθj<π-\pi<Q^{i}_{j} \theta^j<\pi. We compute the diameter of the fundamental domain in terms of the eigenvalues f12≤.˙.≤fN2f_1^2\le\...\le f_N^2 of the metric on field space, and also, crucially, the largest eigenvalue of (QQ⊤)−1(QQ^{\top})^{-1}. At large NN, QQ⊤QQ^{\top} approaches a Wishart matrix, due to universality, and we show that the diameter is at least NfNN f_{N}, exceeding the naive Pythagorean range by a factor >N>\sqrt{N}. This result is robust in the presence of P>NP>N constraints, while for P=NP=N the diameter is further enhanced by eigenvector delocalization to N3/2fNN^{3/2}f_N. We directly verify our results in explicit Calabi-Yau compactifications of type IIB string theory. In the classic example with h1,1=51h^{1,1}=51 where parametrically controlled moduli stabilization was demonstrated by Denef et al. in [1], the largest metric eigenvalue obeys fN≈0.013Mplf_N \approx 0.013 M_{pl}. The random matrix analysis then predicts, and we exhibit, axion diameters >Mpl>M_{pl} for the precise vacuum parameters found in [1]. Our results provide a framework for achieving large-field axion inflation in well-understood flux vacua.Comment: 42 pages, 4 figure

    Chaotic inflation with kinetic alignment of axion fields

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    N-flation is a radiatively stable scenario for chaotic inflation in which the displacements of N≫1 axions with decay constants f1≤…≤fN<MP lead to a super-Planckian effective displacement equal to the Pythagorean sum fPy of the fi. We show that mixing in the axion kinetic term generically leads to the phenomenon of kinetic alignment, allowing for effective displacements as large as N−−√fN≥fPy, even if f1,…,fN−1 are arbitrarily small. At the level of kinematics, the necessary alignment occurs with very high probability, because of eigenvector delocalization. We present conditions under which inflation can take place along an aligned direction. Our construction sharply reduces the challenge of realizing N-flation in string theory

    All Excellence is God\u27s Excellence: Examining the Fractal Nature of Biblical Wisdom for Decision-making in Complex Environments

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    This study analyzed decision-making techniques in complex environments to discover and examine fractal patterns within biblical wisdom. Employing a constructivist grounded theory approach, interviews of organizational leaders from various occupational verticals such as business leaders, pastors, missionaries, politicians, coaches, teachers, military, and law enforcement were conducted to discern their decision-making principles and methods. The significance of this research is its immense application potential. From the broader context of one’s worldview, the search for meaning, purpose, and success in one’s life journey is fundamental to the human psyche. Within motivated leaders, there is consistently a desire to do well—ultimately, to be excellent in one’s personal journey. However, a person’s destination is not determined by their desire but by their path and that path is greatly determined by the choices they make. The greatest influence one can have in impacting their destiny and achieving future success is through sound decision-making. The term and act that describes sound perspective, assessment, and decision-making is wisdom. God is the Source of wisdom. Wisdom executed consistently over time is excellence. Therefore, it could be declared that all excellence must be God’s excellence. This study explored the components of wisdom and how they correlate and attain superlative results in the decision-making process within challenging environments. The desired fruit of the study ascertained that these components can be constructed and extrapolated through the grounded theory process to produce concepts and principles for executing wise judgment in one’s life journey all to the glory of God

    The Benefactor: Assessing the Financial Performance of Charitable Organizations

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    This project provides students with a simulation of the process used by many private foundations in distributing grants to charities. In particular, the project is based on a fictitious benefactor of a large private foundation who has decided to appoint accounting students to grant-making committees. The committees are responsible for using not-for-profit specific financial performance measures to evaluate local charities and determine which charities should be awarded grants. The charities determined to have the strongest financial performance are awarded operating grants from the private foundation. The project complements traditional lecturing methods by providing a realistic context for introducing students to the importance of the not-for-profit sector and the accounting and financial performance issues faced by charitable organizations

    Parasites of the Spotted Sucker, Minytrema melanops (Cypriniformes: Catostomidae) from Arkansas and Oklahoma

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    During October 2015, March and April 2016 and again between March and April 2017, 15 Spotted Sucker (Minytrema melanops) were collected from sites in the Ouachita (n = 5), Red (n = 1), and St. Francis (n = 5) river drainages, Arkansas, and the Arkansas River drainage, Oklahoma (n = 4), and examined for protozoan and metazoan parasites. Found were Calyptospora sp., Myxobolus sp., Pseudomurraytrema alabarrum, Biacetabulum banghami, Penarchigetes oklensis, and Acanthocephalus sp. New host and distributional records are documented for these parasites

    Head impact accelerations for brain strain-related responses in contact sports: a model-based investigation

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    Both linear (alin) and rotational (arot) accelerations contribute to head impacts on the field in contact sports; however, they are often isolated in injury studies. It is critical to evaluate the feasibility of estimating brain responses using isolated instead of full degrees-of-freedom (DOFs) accelerations. In this study, we investigated the sensitivities of regional brain strain-related responses to resultant alin and arot as well as the relative contributions of these acceleration components to the responses via random sampling and linear regression using parameterized, triangulated head impacts with kinematic variable values based on on-field measurements. Two independently established and validated finite element models of the human head were employed to evaluate model consistency and dependency in results: the Dartmouth Head Injury Model (DHIM) and Simulated Injury Monitor (SIMon). For the majority of the brain, volume-weighted regional peak strain, strain rate, and von Mises stress accumulated from the simulation significantly correlated to the product of the magnitude and duration of arot, or effectively, the rotational velocity, but not to alin. Responses from arot-only were comparable to the full-DOFs counterparts especially when normalized by injury-causing thresholds (e.g., volume fractions of large differences virtually diminished (i.e., <1%) at typical difference percentage levels of 1–4% on average). These model-consistent results support the inclusion of both rotational acceleration magnitude and duration into kinematics-based injury metrics, and demonstrate the feasibility of estimating strain-related responses from isolated arot for analyses of strain-induced injury relevant to contact sports without significant loss of accuracy, especially for the cerebrum
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