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On 'Nothing'  [PDF]
Adam R. Brown,Alex Dahlen
Physics , 2011, DOI: 10.1103/PhysRevD.85.104026
Abstract: Nothing---the absence of spacetime---can be either an endpoint of tunneling, as in the bubble of nothing, or a starting point for tunneling, as in the quantum creation of a universe. We argue that these two tunnelings can be treated within a unified framework, and that, in both cases, nothing should be thought of as the limit of anti-de Sitter space in which the curvature length approaches zero. To study nothing, we study decays in models with perturbatively stabilized extra dimensions, which admit not just bubbles of nothing---topology-changing transitions in which the extra dimensions pinch off and a hole forms in spacetime---but also a whole family of topology-preserving transitions that nonetheless smoothly hollow out and approach the bubble of nothing in one limit. The bubble solutions that are close to this limit, bubbles of next-to- nothing, give us a controlled setting in which to understand nothing. Armed with this understanding, we are able to embed proposed mechanisms for the reverse process, tunneling from nothing to something, within the relatively secure foundation of the Coleman-De Luccia formalism and show that the Hawking-Turok instanton does not mediate the quantum creation of a universe.
A hierarchy of voids: More ado about nothing  [PDF]
Aseem Paranjape,Tsz Yan Lam,Ravi K. Sheth
Physics , 2011, DOI: 10.1111/j.1365-2966.2011.20154.x
Abstract: We extend earlier work on the problem of estimating the void-volume function -- the abundance and evolution of large voids which grow gravitationally in an expanding universe -- in two ways. The first removes an ambiguity about how the void-in-cloud process, which erases small voids, should be incorporated into the excursion set approach. The main technical change here is to think of voids within a fully Eulerian, rather than purely Lagrangian, framework. The second accounts for correlations between different spatial scales in the initial conditions. We provide numerical and analytical arguments showing how and why both changes modify the predicted abundances substantially. In particular, we show that the predicted importance of the void-in-cloud process depends strongly on whether or not one accounts for correlations between scales. With our new formulation, the void-in-cloud process dramatically reduces the predicted abundances of voids if such correlations are ignored, but only matters for the smallest voids in the more realistic case in which the spatial correlations are included.
Nucleomorph genomes: much ado about practically nothing
Paul R Gilson
Genome Biology , 2001, DOI: 10.1186/gb-2001-2-8-reviews1022
Abstract: It may surprise many that the sixth eukaryotic genome to be sequenced comes not from some familiar model organism but from a nucleus whose DNA content is less than that of most bacteria [1]. This nucleus comes from Guillardia theta, a member of a group of biflagellate protists called cryptomonads (Figure 1). The tiny nucleus, called a nucleomorph, is not the main cellular nucleus but is the residual nucleus of a red algal endosymbiont that resides inside the endoplasmic reticulum (ER) of its host cell (Figure 1) [2]. Another group of protists, called chlorarachniophytes, also have nucleomorphs, and these are the remnant nuclei of green algal endosymbionts (Figure 1) [3,4]. Both protist groups are believed to have acquired their endosymbionts about 600 million years ago [5] when, instead of digesting their algal-prey meals as they would normally do, the host cells retained the algae, to feed the heterotrophic host cell with carbohydrates made by the algal chloroplast. Over time the algae and hosts became interdependent and the algae lost their autonomy, becoming highly streamlined for photosynthesis. Most of the trappings normally found in a eukaryotic cell, such as mitochondria, endoplasmic reticulum and flagella, have been entirely lost from the endosymbionts. All that is left is a prominent double-membrane-bound chloroplast surrounded by a small volume of cytoplasm (called the periplastidal space), in which resides the diminutive nucleomorph (Figure 1). A relic plasma membrane still envelops the alga that is in turn surrounded by a modified food vacuole in chlorarachniophytes or by the host cell's ER in cryptomonads [6]. The chloroplast is, in effect, bound by four membranes (Figure 1).The primary chloroplasts of red algae, glaucophytes, green algae and plants are bound by two membranes and are derived from cyanobacterial endosymbionts, but chloroplasts bound by three or four membranes are also common [7]. These so-called 'multi-membraned' or 'complex' plastids ar
Yet More Ado About Nothing: The Remarkable Relativistic Vacuum State  [PDF]
Stephen J. Summers
Physics , 2008,
Abstract: An overview is given of what mathematical physics can currently say about the vacuum state for relativistic quantum field theories on Minkowski space. Along with a review of classical results such as the Reeh--Schlieder Theorem and its immediate and controversial consequences, more recent results are discussed. These include the nature of vacuum correlations and the degree of entanglement of the vacuum, as well as the striking fact that the modular objects determined by the vacuum state and algebras of observables localized in certain regions of Minkowski space encode a remarkable range of physical information, from the dynamics and scattering behavior of the theory to the external symmetries and even the space--time itself. These modular objects also provide an intrinsic characterization of the vacuum state itself, a fact which is of particular relevance to the search for criteria to select physically significant reference states for quantum field theories on curved space--times.
Turkish Studies , 2011,
Abstract: Oguz Atay should be evaluated with his story book named ‘Waiting for the Fear’ within the Turkish stories after 70s. He has tried to tell the depression ironically, which Turkish people experienced after the 70s, in the stories in his storybook published in 1975 using criticism and humor elements. The stories and characters in the stories of Atay, who is considered as one of the first postmodernist authors of Turkish literature, are parallel with his novels and characters in novels. These guys, called as ‘good for nothing’ in many sources and definition, have been at the forefront in the stories of the author as well in his other works. In this article titles of postmodern zm and Oguz Atay, surrealism and Oguz Atay after that Kafka and Atay, Dostoyevski and Atay under titles mentioned on influence of current, concept and persons of Atay novels and stories. After that the events in the stories of Oguz Atay are mentioned briefly and then the concepts he focused are elaborated. In the conclusion section, a judgment is tried to be set forth about the story-telling of Oguz Atay, based on these concepts. O uz Atay, ‘Korkuyu Bekleyen’ ad n ta yan hikaye kitab yla 70 sonras Türk hikayesi i erisinde de erlendirilmelidir. 1975 y l nda yay mlanan hikaye kitab ndaki ykülerde, 70 sonras Türk insan n n ya ad bunal m ele tiri ve mizah unsurlar n kullanarak ironik bir ekilde anlatmaya al m t r. Türk edebiyat n n ilk postmodernist yazarlar ndan biri olarak kabul edilen Atay’ n hikayeleri ve hikayelerindeki kahramanlar romanlar ve romanlar ndaki kahramanlarla paralellik g sterir. Bir ok kaynakta ve tan mlamada ‘tutunamayan’ olarak adland r lan bu tipler, yazar n di er eserlerinde oldu u gibi hikayelerinde de n planda yer al rlar. Makalede postmodernizm ve O uz Atay, ger eküstücülük ve O uz Atay ba l klar ndan sonra Kafka ve Atay, Dostoyevski ve Atay ba l klar alt nda Atay’ n roman ve hikayecili ini etkileyen ak m, kavram ve ki iler üzerinde durulmu tur. Daha sonra O uz Atay’ n hikayelerindeki olaylardan k saca bahsedilerek hikayelerinde i ledi i kavramlar vurgulanm t r. Sonu b lümünde ise bu kavramlardan hareketle O uz Atay’ n hikayecili i hakk nda bir yarg ya var lmaya al lm t r.
Negucioiu Aurel
Annals of the University of Oradea : Economic Science , 2012,
Abstract: One of the most important moments of the start or restart of the academic activity has always been the opening of courses in each subject (discipline) that would be studied. On these occasions each professor shows to the students the subject of the discipline, place and role that intellectual seizure of that object in the formation of their professional competence required by the exigencies of the time. Most teachers stop on the most important sources, sources of knowledge that young learners can turn to and would be better to turn. They indicate written sources, books, magazines and other publications available in classical libraries and add, especially now, the worlda€ s largest library: the Internet. However, teachers advise students to seek permanently another source, a "book" - permanently opened, the book of reality that contains the most truth and what is very important - many problems waiting to be discovered and resolved. Leafing over "the first pages" of one of the "volumes" of this huge established "book", I found that the paradigm "Everything moves. Nothing stands still" as the paradigm "movement is absolute, and the repose - roughly" is far from having exhausted full knowledge of "everything". But knowledge can enrich through investigation of the unknown aspects. Substantially reducing the size of the unknown we have subscribed to communicate, stopping on several sides and objectives of the issues: Further examination of the main contents of the concept of development; Nominate a limited number of forms of movement in the "kingdom" of the Megasystem Eco-soc-eco; Further investigation of the causes of motion; Pace to and rhythm in which the different forms of movement develop; Which are the directions in which evolve different directions of movement forms.
Estimate nothing  [PDF]
M. Duembgen,L. C. G. Rogers
Quantitative Finance , 2014,
Abstract: In the econometrics of financial time series, it is customary to take some parametric model for the data, and then estimate the parameters from historical data. This approach suffers from several problems. Firstly, how is estimation error to be quantified, and then taken into account when making statements about the future behaviour of the observed time series? Secondly, decisions may be taken today committing to future actions over some quite long horizon, as in the trading of derivatives; if the model is re-estimated at some intermediate time, our earlier decisions would need to be revised - but the derivative has already been traded at the earlier price. Thirdly, the exact form of the parametric model to be used is generally taken as given at the outset; other competitor models might possibly work better in some circumstances, but the methodology does not allow them to be factored into the inference. What we propose here is a very simple (Bayesian) alternative approach to inference and action in financial econometrics which deals decisively with all these issues. The key feature is that nothing is being estimated.
The Cosmology of Nothing  [PDF]
Michael S. Turner
Physics , 1997,
Abstract: For more seventy years physicists have appreciated that Nature's vacuum is far from empty. The discovery of the Lamb shift in Hydrogen provided dramatic verification of the reality of the quantum vacuum. The advent of gauge theories has led us to believe that the physics of the vacuum is even richer, with the possibility of instantons, vacuum phase transitions, vacuum defects (monopoles, domain walls, cosmic strings and nontopological solitons), vacuum energy, and degenerate vacua states (with different local realizations of the laws of physics). Cosmology offers a unique laboratory for exploring the ``physics of nothing.'' In this lecture I focus on the implications of vacuum energy for cosmology -- in particular, inflation -- and discuss the flood of observations that are testing the inflationary paradigm and in process probing the physics of nothing. I also discuss the possibility that today vacuum energy plays a dynamically important role (as a cosmological constant).
The dual of nothing  [PDF]
Vijay Balasubramanian,Simon F. Ross
Physics , 2002, DOI: 10.1103/PhysRevD.66.086002
Abstract: We consider ``bubbles of nothing'' constructed by analytically continuing black hole solutions in Anti-de Sitter space. These provide interesting examples of smooth time-dependent backgrounds which can be studied through the AdS/CFT correspondence. Our examples include bubbles constructed from Schwarzschild-AdS, Kerr-AdS and Reissner-Nordstrom AdS. The Schwarzschild bubble is dual to Yang-Mills theory on three dimensional de Sitter space times a circle. We construct the boundary stress tensor of the bubble spacetime and relate it to the properties of field theory on de Sitter.
Bubbles from Nothing  [PDF]
Jose J. Blanco-Pillado,Handhika S. Ramadhan,Benjamin Shlaer
Physics , 2011, DOI: 10.1088/1475-7516/2012/01/045
Abstract: Within the framework of flux compactifications, we construct an instanton describing the quantum creation of an open universe from nothing. The solution has many features in common with the smooth 6d bubble of nothing solutions discussed recently, where the spacetime is described by a 4d compactification of a 6d Einstein-Maxwell theory on S^2 stabilized by flux. The four-dimensional description of this instanton reduces to that of Hawking and Turok. The choice of parameters uniquely determines all future evolution, which we additionally find to be stable against bubble of nothing instabilities.
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