TY - GEN AB - We extend the mathematical theory of quantum hypothesis testing to the general W*-algebraic setting and explore its relation with recent developments in non-equilibrium quantum statistical mechanics. In particular, we relate the large deviation principle for the full counting statistics of entropy flow to quantum hypothesis testing of the arrow of time. AU - Jakšić, Vojkan AU - Ogata, Yoshiko AU - Pillet, Claude A AU - Robert Seiringer ID - 2398 IS - 6 T2 - Reviews in Mathematical Physics TI - Quantum hypothesis testing and non-equilibrium statistical mechanics VL - 24 ER - TY - JOUR AB - We consider the low-density limit of a Fermi gas in the BCS approximation. We show that if the interaction potential allows for a two-particle bound state, the system at zero temperature is well approximated by the Gross-Pitaevskii functional, describing a Bose-Einstein condensate of fermion pairs. AU - Hainzl, Christian AU - Robert Seiringer ID - 2397 IS - 2 JF - Letters in Mathematical Physics TI - Low density limit of BCS theory and Bose-Einstein condensation of Fermion pairs VL - 100 ER - TY - JOUR AB - We investigate the frequency of positive squareful numbers x, y, z≤B for which x+y=z and present a conjecture concerning its asymptotic behavior. AU - Timothy Browning AU - Valckenborgh, K Van ID - 240 IS - 2 JF - Experimental Mathematics TI - Sums of three squareful numbers VL - 21 ER - TY - JOUR AB - If the polaron coupling constant α is large enough, bipolarons or multi-polarons will form. When passing through the critical α c from above, does the radius of the system simply get arbitrarily large or does it reach a maximum and then explode? We prove that it is always the latter. We also prove the analogous statement for the Pekar-Tomasevich (PT) approximation to the energy, in which case there is a solution to the PT equation at α c. Similarly, we show that the same phenomenon occurs for atoms, e. g., helium, at the critical value of the nuclear charge. Our proofs rely only on energy estimates, not on a detailed analysis of the Schrödinger equation, and are very general. They use the fact that the Coulomb repulsion decays like 1/r, while 'uncertainty principle' localization energies decay more rapidly, as 1/r 2. AU - Frank, Rupert L AU - Lieb, Élliott H AU - Robert Seiringer ID - 2400 IS - 2 JF - Communications in Mathematical Physics TI - Binding of polarons and atoms at threshold VL - 313 ER - TY - JOUR AB - We study the effects of random scatterers on the ground state of the one-dimensional Lieb-Liniger model of interacting bosons on the unit interval in the Gross-Pitaevskii regime. We prove that Bose-Einstein condensation survives even a strong random potential with a high density of scatterers. The character of the wavefunction of the condensate, however, depends in an essential way on the interplay between randomness and the strength of the two-body interaction. For low density of scatterers and strong interactions the wavefunction extends over the whole interval. A high density of scatterers and weak interactions, on the other hand, lead to localization of the wavefunction in a fragmented subset of the interval. AU - Robert Seiringer AU - Yngvason, Jakob AU - Zagrebnov, Valentin A ID - 2403 IS - 11 JF - Journal of Statistical Mechanics Theory and Experiment TI - Disordered Bose-Einstein condensates with interaction in one dimension VL - 2012 ER - TY - JOUR AB - We consider a model of quantum-mechanical particles interacting via point interactions of infinite scattering length. In the case of fermions we prove a Lieb-Thirring inequality for the energy, i.e., we show that the energy is bounded from below by a constant times the integral of the particle density to the power. AU - Frank, Rupert L AU - Robert Seiringer ID - 2402 IS - 9 JF - Journal of Mathematical Physics TI - Lieb-Thirring inequality for a model of particles with point interactions VL - 53 ER - TY - JOUR AB - We find further implications of the BMV conjecture, which states that for hermitian matrices B≥0 and A, the function λ {mapping} Tr exp(A - λB) is the Laplace transform of a positive measure supported on [0,∞]. AU - Lieb, Élliott H AU - Robert Seiringer ID - 2401 IS - 1 JF - Journal of Statistical Physics TI - Further implications of the Bessis-Moussa-Villani conjecture VL - 149 ER - TY - JOUR AB - The kingdom of fungi provides model organisms for biotechnology, cell biology, genetics, and life sciences in general. Only when their phylogenetic relationships are stably resolved, can individual results from fungal research be integrated into a holistic picture of biology. However, and despite recent progress, many deep relationships within the fungi remain unclear. Here, we present the first phylogenomic study of an entire eukaryotic kingdom that uses a consistency criterion to strengthen phylogenetic conclusions. We reason that branches (splits) recovered with independent data and different tree reconstruction methods are likely to reflect true evolutionary relationships. Two complementary phylogenomic data sets based on 99 fungal genomes and 109 fungal expressed sequence tag (EST) sets analyzed with four different tree reconstruction methods shed light from different angles on the fungal tree of life. Eleven additional data sets address specifically the phylogenetic position of Blastocladiomycota, Ustilaginomycotina, and Dothideomycetes, respectively. The combined evidence from the resulting trees supports the deep-level stability of the fungal groups toward a comprehensive natural system of the fungi. In addition, our analysis reveals methodologically interesting aspects. Enrichment for EST encoded data-a common practice in phylogenomic analyses-introduces a strong bias toward slowly evolving and functionally correlated genes. Consequently, the generalization of phylogenomic data sets as collections of randomly selected genes cannot be taken for granted. A thorough characterization of the data to assess possible influences on the tree reconstruction should therefore become a standard in phylogenomic analyses. AU - Ebersberger, Ingo AU - De Matos Simoes, Ricardo AU - Kupczok, Anne AU - Gube, Matthias AU - Kothe, Erika AU - Voigt, Kerstin AU - Von Haeseler, Arndt ID - 2411 IS - 5 JF - Molecular Biology and Evolution TI - A consistent phylogenetic backbone for the fungi VL - 29 ER - TY - JOUR AB - The representation of integral binary forms as sums of two squares is discussed and applied to establish the Manin conjecture for certain Châtelet surfaces over ℚ. AU - de la Bretèche, Régis AU - Timothy Browning ID - 241 IS - 2 JF - Israel Journal of Mathematics TI - Binary forms as sums of two squares and Châtelet surfaces VL - 191 ER - TY - JOUR AB - We investigate the first and second moments of shifted convolutions of the generalized divisor function d 3(n). AU - Baier, Stephan AU - Timothy Browning AU - Marasingha, Gihan AU - Zhao, Liangyi ID - 242 IS - 3 JF - Proceedings of the Edinburgh Mathematical Society TI - Averages of shifted convolutions of d3 (n) VL - 55 ER - TY - JOUR AB - Let P(t) ∈ ℚ[t] be an irreducible quadratic polynomial and suppose that K is a quartic extension of ℚ containing the roots of P(t). Let N K/ℚ(X) be a full norm form for the extension K/ℚ. We show that the variety P(t) =N K/ℚ(X)≠ 0 satisfies the Hasse principle and weak approximation. The proof uses analytic methods. AU - Timothy Browning AU - Heath-Brown, Roger ID - 243 IS - 5 JF - Geometric and Functional Analysis TI - Quadratic polynomials represented by norm forms VL - 22 ER - TY - CONF AB - We present an algorithm for computing [X, Y], i.e., all homotopy classes of continuous maps X → Y, where X, Y are topological spaces given as finite simplicial complexes, Y is (d - 1)-connected for some d ≥ 2 (for example, Y can be the d-dimensional sphere S d), and dim X ≤ 2d - 2. These conditions on X, Y guarantee that [X, Y] has a natural structure of a finitely generated Abelian group, and the algorithm finds generators and relations for it. We combine several tools and ideas from homotopy theory (such as Postnikov systems, simplicial sets, and obstruction theory) with algorithmic tools from effective algebraic topology (objects with effective homology). We hope that a further extension of the methods developed here will yield an algorithm for computing, in some cases of interest, the ℤ 2-index, which is a quantity playing a prominent role in Borsuk-Ulam style applications of topology in combinatorics and geometry, e.g., in topological lower bounds for the chromatic number of a graph. In a certain range of dimensions, deciding the embeddability of a simplicial complex into ℝ d also amounts to a ℤ 2-index computation. This is the main motivation of our work. We believe that investigating the computational complexity of questions in homotopy theory and similar areas presents a fascinating research area, and we hope that our work may help bridge the cultural gap between algebraic topology and theoretical computer science. AU - Čadek, Martin AU - Marek Krcál AU - Matoušek, Jiří AU - Sergeraert, Francis AU - Vokřínek, Lukáš AU - Uli Wagner ID - 2440 TI - Computing all maps into a sphere ER - TY - JOUR AB - The colored Tverberg theorem asserts that for eve;ry d and r there exists t=t(d,r) such that for every set C ⊂ ℝ d of cardinality (d + 1)t, partitioned into t-point subsets C 1, C 2,...,C d+1 (which we think of as color classes; e. g., the points of C 1 are red, the points of C 2 blue, etc.), there exist r disjoint sets R 1, R 2,...,R r⊆C that are rainbow, meaning that {pipe}R i∩C j{pipe}≤1 for every i,j, and whose convex hulls all have a common point. All known proofs of this theorem are topological. We present a geometric version of a recent beautiful proof by Blagojević, Matschke, and Ziegler, avoiding a direct use of topological methods. The purpose of this de-topologization is to make the proof more concrete and intuitive, and accessible to a wider audience. AU - Matoušek, Jiří AU - Martin Tancer AU - Uli Wagner ID - 2438 IS - 2 JF - Discrete & Computational Geometry TI - A geometric proof of the colored Tverberg theorem VL - 47 ER - TY - JOUR AB - We investigate the solubility of the congruence xy ≡ 1 (mod p), where p is a prime and x, y are restricted to lie in suitable short intervals. Our work relies on a mean value theorem for incomplete Kloosterman sums. AU - Timothy Browning AU - Haynes, Alan K ID - 244 IS - 2 JF - International Journal of Number Theory TI - Incomplete kloosterman sums and multiplicative inverses in short intervals VL - 9 ER - TY - JOUR AB - A Monte Carlo approximation algorithm for the Tukey depth problem in high dimensions is introduced. The algorithm is a generalization of an algorithm presented by Rousseeuw and Struyf (1998) . The performance of this algorithm is studied both analytically and experimentally. AU - Chen, Dan AU - Morin, Pat AU - Uli Wagner ID - 2439 IS - 5 JF - Computational Geometry: Theory and Applications TI - Absolute approximation of Tukey depth: Theory and experiments VL - 46 ER - TY - CONF AB - Eigenvalues associated to graphs are a well-studied subject. In particular the spectra of the adjacency matrix and of the Laplacian of random graphs G(n, p) are known quite precisely. We consider generalizations of these matrices to simplicial complexes of higher dimensions and study their eigenvalues for the Linial-Meshulam model X k(n, p) of random k-dimensional simplicial complexes on n vertices. We show that for p = Ω(log n/n), the eigenvalues of both, the higher-dimensional adjacency matrix and the Laplacian, are a.a.s. sharply concentrated around two values. In a second part of the paper, we discuss a possible higherdimensional analogue of the Discrete Cheeger Inequality. This fundamental inequality expresses a close relationship between the eigenvalues of a graph and its combinatorial expansion properties; in particular, spectral expansion (a large eigenvalue gap) implies edge expansion. Recently, a higher-dimensional analogue of edge expansion for simplicial complexes was introduced by Gromov, and independently by Linial, Meshulam and Wallach and by Newman and Rabinovich. It is natural to ask whether there is a higher-dimensional version of Cheeger's inequality. We show that the most straightforward version of a higher-dimensional Cheeger inequality fails: for every k > 1, there is an infinite family of k-dimensional complexes that are spectrally expanding (there is a large eigenvalue gap for the Laplacian) but not combinatorially expanding. AU - Gundert, Anna AU - Uli Wagner ID - 2441 TI - On Laplacians of random complexes ER - TY - JOUR AB - Constitutive endocytic recycling is a crucial mechanism allowing regulation of the activity of proteins at the plasma membrane and for rapid changes in their localization, as demonstrated in plants for PIN-FORMED (PIN) proteins, the auxin transporters. To identify novel molecular components of endocytic recycling, mainly exocytosis, we designed a PIN1-green fluorescent protein fluorescence imaging-based forward genetic screen for Arabidopsis thaliana mutants that showed increased intracellular accumulation of cargos in response to the trafficking inhibitor brefeldin A (BFA). We identified bex5 (for BFA-visualized exocytic trafficking defective), a novel dominant mutant carrying a missense mutation that disrupts a conserved sequence motif of the small GTPase, RAS GENES FROM RAT BRAINA1b. bex5 displays defects such as enhanced protein accumulation in abnormal BFA compartments, aberrant endosomes, and defective exocytosis and transcytosis. BEX5/RabA1b localizes to trans-Golgi network/early endosomes (TGN/EE) and acts on distinct trafficking processes like those regulated by GTP exchange factors on ADP-ribosylation factors GNOM-LIKE1 and HOPM INTERACTOR7/BFA-VISUALIZED ENDOCYTIC TRAFFICKING DEFECTIVE1, which regulate trafficking at the Golgi apparatus and TGN/EE, respectively. All together, this study identifies Arabidopsis BEX5/RabA1b as a novel regulator of protein trafficking from a TGN/EE compartment to the plasma membrane. AU - Feraru, Elena AU - Feraru, Mugurel Ioan AU - Asaoka, Rin AU - Paciorek, Tomasz AU - De Rycke, Riet M AU - Tanaka, Hirokazu AU - Nakano, Akihiko AU - Jirí Friml ID - 2453 IS - 7 JF - Plant Cell TI - BEX5/RabA1b regulates trans-Golgi network-to-plasma membrane protein trafficking in Arabidopsis VL - 24 ER - TY - JOUR AB - The third EMBO Conference on Plant Molecular Biology, which focused on ‘Plant development and environmental interactions’,was held in May 2012 in Matera, Italy. Here, we review some of the topics and themes that emerged from the various contributions; namely, steering technologies, transcriptional networks and hormonal regulation, small RNAs, cell and tissue polarity, environmental control and natural variation. We intend to provide the reader who might have missed this remarkable event with a glimpse of the recent progress made in this blossoming research field. AU - Beeckman, Tom AU - Friml, Jirí ID - 2456 IS - 20 JF - Development TI - Plant developmental biologists meet on stairways in Matera VL - 139 ER - TY - JOUR AB - Coordinated, subcellular trafficking of proteins is one of the fundamental properties of the multicellular eukaryotic organisms. Trafficking involves a large diversity of compartments, pathways, cargo molecules, and vesicle-sorting events. It is also crucial in regulating the localization and, thus, the activity of various proteins, but the process is still poorly genetically defined in plants. In the past, forward genetics screens had been used to determine the function of genes by searching for a specific morphological phenotype in the organism population in which mutations had been induced chemically or by irradiation. Unfortunately, these straightforward genetic screens turned out to be limited in identifying new regulators of intracellular protein transport, because mutations affecting essential trafficking pathways often lead to lethality. In addition, the use of these approaches has been restricted by functional redundancy among trafficking regulators. Screens for mutants that rely on the observation of changes in the cellular localization or dynamics of fluorescent subcellular markers enable, at least partially, to circumvent these issues. Hence, such image-based screens provide the possibility to identify either alleles with weak effects or components of the subcellular trafficking machinery that have no strong impact on the plant growth. AU - Zwiewka, Marta AU - Friml, Jirí ID - 2459 IS - May JF - Frontiers in Plant Science TI - Fluorescence imaging-based forward genetic screens to identify trafficking regulators in plants VL - 3 ER - TY - JOUR AB - Initiation and successive development of organs induce mechanical stresses at the cellular level. Using the tomato shoot apex, a new study now proposes that mechanical strain regulates the plasma membrane abundance of the PIN1 auxin transporter, thereby reinforcing a positive feed-back loop between growth and auxin accumulation. AU - Li, Hongjiang AU - Friml, Jirí AU - Grunewald, Wim ID - 2458 IS - 16 JF - Current Biology TI - Cell polarity: Stretching prevents developmental cramps VL - 22 ER -