scholarly journals On α′-effects from D-branes in 4d $$ \mathcal{N} $$ = 1

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Matthias Weissenbacher

Abstract In this work we study type IIB Calabi-Yau orientifold compactifications in the presence of space-time filling D7-branes and O7-planes. In particular, we conclude that α′2gs-corrections to their DBI actions lead to a modification of the four-dimensional $$ \mathcal{N} $$ N = 1 Kähler potential and coordinates. We focus on the one-modulus case of the geometric background i.e. h1,1 = 1 where we find that the α′2gs-correction is of topological nature. It depends on the first Chern form of the four-cycle of the Calabi-Yau orientifold which is wrapped by the D7-branes and O7-plane. This is in agreement with our previous F-theory analysis and provides further evidence for a potential breaking of the no-scale structure at order α′2gs. Corrected background solutions for the dilaton, the warp-factor as well as the internal space metric are derived. Additionally, we briefly discuss α′-corrections from other Dp-branes.

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Thibaut Coudarchet ◽  
Emilian Dudas ◽  
Hervé Partouche

Abstract Starting from a peculiar orientifold projection proposed long ago by Angelantonj and Cardella, we elaborate on a novel perturbative scenario that involves only D-branes, together with the two types of orientifold planes O± and anti-orientifold planes $$ {\overline{\mathrm{O}}}_{\pm } $$ O ¯ ± . We elucidate the microscopic ingredients of such models, connecting them to a novel realization of brane supersymmetry breaking. Depending on the position of the D-branes in the internal space, supersymmetry can be broken at the string scale on branes, or alternatively only at the massive level. The main novelty of this construction is that it features no NS-NS disk tadpoles, while avoiding open-string instabilities. The one-loop potential, which depends on the positions of the D-branes, is minimized for maximally broken, non-linearly realized supersymmetry. The orientifold projection and the effective field theory description reveal a soft breaking of supersymmetry in the closed-string sector. In such models it is possible to decouple the gravitino mass from the value of the scalar potential, while avoiding brane instabilities.


2021 ◽  
pp. 35-48
Author(s):  
Julia Zamjatina ◽  
Alexey Kashin ◽  
Olesja Kondrat’eva ◽  
Il’shat Muhametshin

The article presents the concept of reconstruction of the Fertiki unit of the biogeoecological station of the Udmurt State University (hereinafter – the Fertiki campus), formed in the process of joint work of geographers and designers. The presence of a field campus is a necessary condition for the professional skills and abilities formation of students in a number of training areas in a classical university. However, the requirements for the campuses internal space formation are changing. If one and a half to two decades ago it was enough to have a minimally equipped site on the territory that meets the basic needs in terms of the field practices and scientific research content, now the need to expand the functionality and types of activities is becoming more and more obvious. At the same time, it is proposed to put natural, cultural and historical features of the area within which the campus is located as the basis for modern design solutions. In conditions of limited funding and a general unstable financial situation, there is a need for more efficient use of the property complex of the university, including field campuses. They should not only satisfy the needs of conducting educational practices and scientific research, but become complex out-of-town (field) divisions of universities aimed at various types of activities. The proposed concept provides the reconstruction of the biogeoecological station in the direction of forming a focus point of natural and cultural landscapes of a vast territory. On the one hand, the campus must organically fit into the surrounding space, and on the other hand, it must reflect its main natural, cultural and historical features in order to get rich content. Only complexity and polyfunctionality can be stimuli and conditions for its development.


2011 ◽  
Vol 16 (2) ◽  
pp. 175-190 ◽  
Author(s):  
Sorin Baiasu

AbstractThe interpretation of Kant's Critical philosophy as a version of traditional idealism has a long history. In spite of Kant's and his commentators’ various attempts to distinguish between traditional and transcendental idealism, his philosophy continues to be construed as committed (whether explicitly or implicitly and whether consistently or inconsistently) to various features usually associated with the traditional idealist project. As a result, most often, the accusation is that his Critical philosophy makes too strong metaphysical and epistemological claims.In his The Revolutionary Kant, Graham Bird engages in a systematic and thorough evaluation of the traditionalist interpretation, as part of perhaps the most comprehensive and compelling defence of a revolutionary reading of Kant's thought. In the third part of this special issue, the exchanges between, on the one hand, Graham Bird and, on the other, Gary Banham, Gordon Brittan, Manfred Kuehn, Adrian Moore and Kenneth Westphal focus on specific aspects of Bird's interpretation of Kant's first Critique. More exactly, the emphasis is on specific aspects of Bird's interpretation of the Introduction, Analytic of Principles and Transcendental Dialectic of Kant's first Critique.The second part of the special issue is devoted to discussions of particular topics in Bird's construal of the remaining significant parts of the first Critique, namely, of the Transcendental Aesthetic and the Analytic of Concepts. Written by Sorin Baiasu and Michelle Grier, these articles examine specific issues in these two remaining parts of the Critique, from the perspective of the debate between the traditionalist and revolutionary interpretation. The special issue begins with an Introduction by the guest co-editors. This provides a summary of the exchanges between Bird and his critics, with a particular focus on the debates stemming from the differences between traditional and revolutionary interpretations of Kant.


2015 ◽  
Vol 42 (5) ◽  
pp. 438-453
Author(s):  
Robert Cummings Neville
Keyword(s):  

On the one hand, Chinese traditions of philosophy are famous for emphasizing that things are changes, that reality is filled with processes rather than substances. This philosophy was present at least from the Yijing onward and was developed in diverse ways by Confucians, Daoists, and then Chinese Buddhists. But there has not been a similar rich development of the idea of eternity, that nontemporal context within which change can be recognized and measured. This article argues, first, that change presupposes an ontological context of eternity and, second, that eternity so conceived can be experienced and even interpreted in terms of the Chinese traditions.


2021 ◽  
Vol 4 (1) ◽  

In the age of information, it is no secret that the modern science is in a very difficult position. On the one hand, it has high hopes for solving the problems of modern humanity and very practical tasks. On the other hand, science shows limited potential and difficulty in carrying out the tasks. Beyond scientific theory remain such phenomena as gravity and gravitational waves and other unexplored and very useful phenomena. Obviously, the reason for these limited capabilities of modern science is its limited foundation. The foundation of science is determined by its basic axioms. If we expand the foundation of science, we will be able to build a more comprehensive, perfect and voluminous theory. In two monographs and a series of articles the author offers a system of extended axioms (with two new axioms) and a more extended theory (with eight new laws). To the great surprise of even the author, this new theory turned out to be extensive enough to cover and explain and the gravity. Moreover, the extended axioms and theory directly and naturally outlined the algorithm in the explanation of the so-called Gravity Funnels. According to the new axioms and laws, Gravity Funnels are both for suction (accelerating) and for expansion (decelerating). Expansion Gravity Funnel decelerates along its longitudinal direction as emits the matter in the transverse direction. In this way it consumes energy and generates matter. Suction Gravity Funnel accelerates along its longitudinal direction as sucks the matter in transverse direction. In this way it consumes matter and generates energy. The both of Funnels are situated in a new Space-time. The Space-time of decelerating and accelerating Funnels is packed by longitudinal vortices, in which the Space (S) is constant. It is radically different of the Space-Time where we live now. The Space-time where we live now is packed by cross vortices, where the time (T) is constant. According the new Axioms and Laws the two described Space- times are mutually orthogonal.


2018 ◽  
Vol 33 (12) ◽  
pp. 1850061 ◽  
Author(s):  
Ryuichi Nakayama ◽  
Tomotaka Suzuki

We construct a localized state of a scalar field in 3D spin-3 gravity. 3D spin-3 gravity is thought to be holographically dual to [Formula: see text]-extended CFT on a boundary at infinity. It is known that while [Formula: see text] algebra is a nonlinear algebra, in the limit of large central charge [Formula: see text] a linear finite-dimensional subalgebra generated by [Formula: see text] [Formula: see text] and [Formula: see text] [Formula: see text] is singled out. The localized state is constructed in terms of these generators. To write down an equation of motion for a scalar field which is satisfied by this localized state, it is necessary to introduce new variables for an internal space [Formula: see text], [Formula: see text], [Formula: see text], in addition to ordinary coordinates [Formula: see text] and [Formula: see text]. The higher-dimensional space, which combines the bulk space–time with the “internal space,” which is an analog of superspace in supersymmetric theory, is introduced. The “physical bulk space–time” is a 3D hypersurface with constant [Formula: see text], [Formula: see text] and [Formula: see text] embedded in this space. We will work in Poincaré coordinates of AdS space and consider [Formula: see text]-quasi-primary operators [Formula: see text] with a conformal weight [Formula: see text] in the boundary and study two and three point functions of [Formula: see text]-quasi-primary operators transformed as [Formula: see text]. Here, [Formula: see text] and [Formula: see text] are [Formula: see text] generators in the hyperbolic basis for Poincaré coordinates. It is shown that in the [Formula: see text] limit, the conformal weight changes to a new value [Formula: see text]. This may be regarded as a Renormalization Group (RG) flow. It is argued that this RG flow will be triggered by terms [Formula: see text] added to the action.


1983 ◽  
Vol 103 ◽  
pp. 509-509
Author(s):  
I.J. Danziger ◽  
D. Baade ◽  
P. D. Atherton ◽  
K. Taylor ◽  
A. Boksenberg

From five spectrograms obtained at five different positions in the nebula, relative ionic concentrations have been derived with respect to the nucleus. They show that the degree of excitation generally decreases with distance from the nucleus. But there are also areas with locally enhanced or attenuated excitation. Taurus data, a series of two-dimensional monochromatic images centered on (OIII) λ 5007, have been used to construct a two-dimensional velocity map. It shows a large-scale structure similar to the one of direct images with the biconical pattern being at least partly present. Areas of locally lower radial velocity which seem to be inversion symmetrically distributed with respect to the centre, are also distinguished. They do not have pronounced counterparts on direct images. The cavity model suggested by Barral et al. (1982, MNRAS 199, 95) for NGC 6302 and Icke's biconical flow model (1981, Ap. J. 247, 152) are discussed.


2007 ◽  
Vol 14 (2) ◽  
pp. 139-151 ◽  
Author(s):  
R. Castilla ◽  
J. M. Redondo ◽  
P. J. Gámez-Montero ◽  
A. Babiano

Abstract. We study numerically the comparison between Lagrangian experiments on turbulent particle dispersion in 2-D turbulent flows performed, on the one hand, on the basis of direct numerical simulations (DNS) and, on the other hand, using kinematic simulations (KS). Eulerian space-time structure of both DNS and KS dynamics are not comparable, mostly due to the absence of strong coherent vortices and advection processes in the KS fields. The comparison allows to refine past studies about the contribution of non-homogeneous space-time 2-D Eulerian structure on the turbulent absolute and relative particle dispersion processes. We particularly focus our discussion on the Richardson's regime for relative dispersion.


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