@misc{2398, abstract = {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.}, author = {Jakšić, Vojkan and Ogata, Yoshiko and Pillet, Claude A and Robert Seiringer}, booktitle = {Reviews in Mathematical Physics}, number = {6}, publisher = {World Scientific Publishing}, title = {{Quantum hypothesis testing and non-equilibrium statistical mechanics}}, doi = {10.1142/S0129055X12300026}, volume = {24}, year = {2012}, } @inbook{2399, abstract = {Bose–Einstein condensation (BEC) in cold atomic gases was first achieved experimentally in 1995 [1, 6]. After initial failed attempts with spin-polarized atomic hydrogen, the first successful demonstrations of this phenomenon used gases of rubidium and sodium atoms, respectively. Since then there has been a surge of activity in this field, with ingenious experiments putting forth more and more astonishing results about the behavior of matter at very cold temperatures. }, author = {Robert Seiringer}, booktitle = {Quantum Many Body Systems}, editor = {Rivasseau, Vincent and Robert Seiringer and Solovej, Jan P and Spencer, Thomas}, pages = {55 -- 92}, publisher = {Springer}, title = {{Cold quantum gases and bose einstein condensation}}, doi = {10.1007/978-3-642-29511-9_2}, volume = {2051}, year = {2012}, } @article{240, abstract = {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.}, author = {Timothy Browning and Valckenborgh, K Van}, journal = {Experimental Mathematics}, number = {2}, pages = {204 -- 211}, publisher = {Taylor & Francis}, title = {{Sums of three squareful numbers}}, doi = {10.1080/10586458.2011.605733}, volume = {21}, year = {2012}, } @article{2400, abstract = {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.}, author = {Frank, Rupert L and Lieb, Élliott H and Robert Seiringer}, journal = {Communications in Mathematical Physics}, number = {2}, pages = {405 -- 424}, publisher = {Springer}, title = {{Binding of polarons and atoms at threshold}}, doi = {10.1007/s00220-012-1436-9}, volume = {313}, year = {2012}, } @article{2401, abstract = {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,∞].}, author = {Lieb, Élliott H and Robert Seiringer}, journal = {Journal of Statistical Physics}, number = {1}, pages = {86 -- 91}, publisher = {Springer}, title = {{Further implications of the Bessis-Moussa-Villani conjecture}}, doi = {10.1007/s10955-012-0585-8}, volume = {149}, year = {2012}, } @article{2402, abstract = {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.}, author = {Frank, Rupert L and Robert Seiringer}, journal = {Journal of Mathematical Physics}, number = {9}, publisher = {American Institute of Physics}, title = {{Lieb-Thirring inequality for a model of particles with point interactions}}, doi = {10.1063/1.3697416}, volume = {53}, year = {2012}, } @article{2403, abstract = {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.}, author = {Robert Seiringer and Yngvason, Jakob and Zagrebnov, Valentin A}, journal = {Journal of Statistical Mechanics Theory and Experiment}, number = {11}, publisher = {IOP Publishing Ltd.}, title = {{Disordered Bose-Einstein condensates with interaction in one dimension}}, doi = {10.1088/1742-5468/2012/11/P11007}, volume = {2012}, year = {2012}, } @article{241, abstract = {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.}, author = {de la Bretèche, Régis and Timothy Browning}, journal = {Israel Journal of Mathematics}, number = {2}, pages = {973 -- 1012}, publisher = {Springer}, title = {{Binary forms as sums of two squares and Châtelet surfaces}}, doi = {10.1007/s11856-012-0019-y}, volume = {191}, year = {2012}, } @article{2411, abstract = {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.}, author = {Ebersberger, Ingo and De Matos Simoes, Ricardo and Kupczok, Anne and Gube, Matthias and Kothe, Erika and Voigt, Kerstin and Von Haeseler, Arndt}, journal = {Molecular Biology and Evolution}, number = {5}, pages = {1319 -- 1334}, publisher = {Oxford University Press}, title = {{A consistent phylogenetic backbone for the fungi}}, doi = {10.1093/molbev/msr285}, volume = {29}, year = {2012}, } @article{242, abstract = {We investigate the first and second moments of shifted convolutions of the generalized divisor function d 3(n).}, author = {Baier, Stephan and Timothy Browning and Marasingha, Gihan and Zhao, Liangyi}, journal = {Proceedings of the Edinburgh Mathematical Society}, number = {3}, pages = {551 -- 576}, publisher = {Cambridge University Press}, title = {{Averages of shifted convolutions of d3 (n)}}, doi = {10.1017/S001309151100037X}, volume = {55}, year = {2012}, } @article{243, abstract = {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.}, author = {Timothy Browning and Heath-Brown, Roger}, journal = {Geometric and Functional Analysis}, number = {5}, pages = {1124 -- 1190}, publisher = {Springer Basel}, title = {{Quadratic polynomials represented by norm forms}}, doi = {10.1007/s00039-012-0168-5}, volume = {22}, year = {2012}, } @inproceedings{6746, abstract = {This paper proposes a novel cooperative approach for two-hop amplify-and-forward (A&F) relaying that exploits both the signal forwarded by the relay and the one directly transmitted by the source in impulse-radio ultra-wideband (IR-UWB) systems. Specifically, we focus on a non-coherent setup employing a double-differential encoding scheme at the source node and a single differential demodulation at the relay and destination. The log-likelihood ratio based decision rule is derived at the destination node. A semi-analytical power allocation strategy is presented by evaluating a closed-form expression for the effective signal to noise ratio (SNR) at the destination, which is maximized by exhaustive search. Numerical simulations show that the proposed system outperforms both the direct transmission with single differential encoding and the non-cooperative multi-hop approach in different scenarios.}, author = {Mondelli, Marco and Zhou, Qi and Ma, Xiaoli and Lottici, Vincenzo}, booktitle = {2012 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)}, issn = {1520-6149}, location = {Kyoto, Japan}, pages = {2905--2908}, publisher = {IEEE}, title = {{A cooperative approach for amplify-and-forward differential transmitted reference IR-UWB relay systems}}, doi = {10.1109/icassp.2012.6288524}, year = {2012}, } @article{7074, abstract = {The Seebeck coefficients, electrical resistivities, total thermal conductivities, and magnetization are reported for temperatures between 5 and 350 K for n-type Bi0.88Sb0.12 nano-composite alloys made by Ho-doping at the 0, 1, and 3 % atomic levels. The alloys were prepared using a dc hot-pressing method, and are shown to be single phase for both Ho contents with grain sizes on the average of 900 nm. We find the parent compound has a maximum of ZT = 0.28 at 231 K, while doping 1 % Ho increases the maximum ZT to 0.31 at 221 K and the 3 % doped sample suppresses the maximum ZT = 0.24 at a temperature of 260 K.}, author = {Lukas, K. C. and Joshi, G. and Modic, Kimberly A and Ren, Z. F. and Opeil, C. P.}, issn = {1573-4803}, journal = {Journal of Materials Science}, number = {15}, pages = {5729--5734}, publisher = {Springer Nature}, title = {{Thermoelectric properties of Ho-doped Bi0.88Sb0.12}}, doi = {10.1007/s10853-012-6463-6}, volume = {47}, year = {2012}, } @article{7308, abstract = {Carbon has been used widely as the basis of porous cathodes for nonaqueous Li–O2 cells. However, the stability of carbon and the effect of carbon on electrolyte decomposition in such cells are complex and depend on the hydrophobicity/hydrophilicity of the carbon surface. Analyzing carbon cathodes, cycled in Li–O2 cells between 2 and 4 V, using acid treatment and Fenton’s reagent, and combined with differential electrochemical mass spectrometry and FTIR, demonstrates the following: Carbon is relatively stable below 3.5 V (vs Li/Li+) on discharge or charge, especially so for hydrophobic carbon, but is unstable on charging above 3.5 V (in the presence of Li2O2), oxidatively decomposing to form Li2CO3. Direct chemical reaction with Li2O2 accounts for only a small proportion of the total carbon decomposition on cycling. Carbon promotes electrolyte decomposition during discharge and charge in a Li–O2 cell, giving rise to Li2CO3 and Li carboxylates (DMSO and tetraglyme electrolytes). The Li2CO3 and Li carboxylates present at the end of discharge and those that form on charge result in polarization on the subsequent charge. Li2CO3 (derived from carbon and from the electrolyte) as well as the Li carboxylates (derived from the electrolyte) decompose and form on charging. Oxidation of Li2CO3 on charging to ∼4 V is incomplete; Li2CO3 accumulates on cycling resulting in electrode passivation and capacity fading. Hydrophilic carbon is less stable and more catalytically active toward electrolyte decomposition than carbon with a hydrophobic surface. If the Li–O2 cell could be charged at or below 3.5 V, then carbon may be relatively stable, however, its ability to promote electrolyte decomposition, presenting problems for its use in a practical Li–O2 battery. The results emphasize that stable cycling of Li2O2 at the cathode in a Li–O2 cell depends on the synergy between electrolyte and electrode; the stability of the electrode and the electrolyte cannot be considered in isolation.}, author = {Ottakam Thotiyl, Muhammed M. and Freunberger, Stefan Alexander and Peng, Zhangquan and Bruce, Peter G.}, issn = {0002-7863}, journal = {Journal of the American Chemical Society}, number = {1}, pages = {494--500}, publisher = {ACS}, title = {{The carbon electrode in nonaqueous Li–O2 cells}}, doi = {10.1021/ja310258x}, volume = {135}, year = {2012}, } @article{7309, abstract = {Energy‐storage technologies, including electrical double‐layer capacitors and rechargeable batteries, have attracted significant attention for applications in portable electronic devices, electric vehicles, bulk electricity storage at power stations, and “load leveling” of renewable sources, such as solar energy and wind power. Transforming lithium batteries and electric double‐layer capacitors requires a step change in the science underpinning these devices, including the discovery of new materials, new electrochemistry, and an increased understanding of the processes on which the devices depend. The Review will consider some of the current scientific issues underpinning lithium batteries and electric double‐layer capacitors.}, author = {Choi, Nam-Soon and Chen, Zonghai and Freunberger, Stefan Alexander and Ji, Xiulei and Sun, Yang-Kook and Amine, Khalil and Yushin, Gleb and Nazar, Linda F. and Cho, Jaephil and Bruce, Peter G.}, issn = {1433-7851}, journal = {Angewandte Chemie International Edition}, number = {40}, pages = {9994--10024}, publisher = {Wiley}, title = {{Challenges facing Lithium batteries and electrical double-layer capacitors}}, doi = {10.1002/anie.201201429}, volume = {51}, year = {2012}, } @article{7310, abstract = {The rechargeable nonaqueous lithium-air (Li-O2) battery is receiving a great deal of interest because, theoretically, its specific energy far exceeds the best that can be achieved with lithium-ion cells. Operation of the rechargeable Li-O2 battery depends critically on repeated and highly reversible formation/decomposition of lithium peroxide (Li2O2) at the cathode upon cycling. Here, we show that this process is possible with the use of a dimethyl sulfoxide electrolyte and a porous gold electrode (95% capacity retention from cycles 1 to 100), whereas previously only partial Li2O2 formation/decomposition and limited cycling could occur. Furthermore, we present data indicating that the kinetics of Li2O2 oxidation on charge is approximately 10 times faster than on carbon electrodes.}, author = {Peng, Z. and Freunberger, Stefan Alexander and Chen, Y. and Bruce, P. G.}, issn = {0036-8075}, journal = {Science}, number = {6094}, pages = {563--566}, publisher = {AAAS}, title = {{A reversible and higher-rate Li-O2 battery}}, doi = {10.1126/science.1223985}, volume = {337}, year = {2012}, } @article{7311, abstract = {Stability of the electrolyte toward reduced oxygen species generated at the cathode is a crucial challenge for the rechargeable nonaqueous Li–O2 battery. Here, we investigate dimethylformamide as the basis of an electrolyte. Although reactions at the O2 cathode on the first discharge–charge cycle are dominated by reversible Li2O2 formation/decomposition, there is also electrolyte decomposition, which increases on cycling. The products of decomposition at the cathode on discharge are Li2O2, Li2CO3, HCO2Li, CH3CO2Li, NO, H2O, and CO2. Li2CO3 accumulates in the electrode with cycling. The stability of dimethylformamide toward reduced oxygen species is insufficient for its use in the rechargeable nonaqueous Li–O2 battery.}, author = {Chen, Yuhui and Freunberger, Stefan Alexander and Peng, Zhangquan and Bardé, Fanny and Bruce, Peter G.}, issn = {0002-7863}, journal = {Journal of the American Chemical Society}, number = {18}, pages = {7952--7957}, publisher = {ACS}, title = {{Li–O2 battery with a dimethylformamide electrolyte}}, doi = {10.1021/ja302178w}, volume = {134}, year = {2012}, } @inproceedings{762, abstract = {Decades of research in distributed computing have led to a variety of perspectives on what it means for a concurrent algorithm to be efficient, depending on model assumptions, progress guarantees, and complexity metrics. It is therefore natural to ask whether one could compose algorithms that perform efficiently under different conditions, so that the composition preserves the performance of the original components when their conditions are met. In this paper, we evaluate the cost of composing shared-memory algorithms. First, we formally define the notion of safely composable algorithms and we show that every sequential type has a safely composable implementation, as long as enough state is transferred between modules. Since such generic implementations are inherently expensive, we present a more general light-weight specification that allows the designer to transfer very little state between modules, by taking advantage of the semantics of the implemented object. Using this framework, we implement a composed longlived test-and-set object, with the property that each of its modules is asymptotically optimal with respect to the progress condition it ensures, while the entire implementation only uses objects with consensus number at most two. Thus, we show that the overhead of composition can be negligible in the case of some important shared-memory abstractions.}, author = {Alistarh, Dan-Adrian and Guerraoui, Rachid and Kuznetsov, Petr and Losa, Giuliano}, pages = {298 -- 307}, publisher = {ACM}, title = {{On the cost of composing shared-memory algorithms}}, doi = {10.1145/2312005.2312057}, year = {2012}, } @inproceedings{763, abstract = {Renaming is a fundamental problem in distributed computing, in which a set of n processes need to pick unique names from a namespace of limited size. In this paper, we present the first early-deciding upper bounds for synchronous renaming, in which the running time adapts to the actual number of failures f in the execution. We show that, surprisingly, renaming can be solved in constant time if the number of failures f is limited to O(√n), while for general f ≤ n - 1 renaming can always be solved in O(log f) communication rounds. In the wait-free case, i.e. for f = n - 1, our upper bounds match the Ω(log n) lower bound of Chaudhuri et al. [13].}, author = {Alistarh, Dan-Adrian and Attiya, Hagit and Guerraoui, Rachid and Travers, Corentin}, pages = {195 -- 206}, publisher = {Springer}, title = {{Early deciding synchronous renaming in O(log f) rounds or less}}, doi = {10.1007/978-3-642-31104-8_17}, volume = {7355 LNCS}, year = {2012}, } @article{764, abstract = {Set agreement is a fundamental problem in distributed computing in which processes collectively choose a small subset of values from a larger set of proposals. The impossibility of fault-tolerant set agreement in asynchronous networks is one of the seminal results in distributed computing. In synchronous networks, too, the complexity of set agreement has been a significant research challenge that has now been resolved. Real systems, however, are neither purely synchronous nor purely asynchronous. Rather, they tend to alternate between periods of synchrony and periods of asynchrony. Nothing specific is known about the complexity of set agreement in such a "partially synchronous" setting. In this paper, we address this challenge, presenting the first (asymptotically) tight bound on the complexity of set agreement in such systems. We introduce a novel technique for simulating, in a fault-prone asynchronous shared memory, executions of an asynchronous and failure-prone message-passing system in which some fragments appear synchronous to some processes. We use this simulation technique to derive a lower bound on the round complexity of set agreement in a partially synchronous system by a reduction from asynchronous wait-free set agreement. Specifically, we show that every set agreement protocol requires at least $\lfloor\frac t k \rfloor + 2$ synchronous rounds to decide. We present an (asymptotically) matching algorithm that relies on a distributed asynchrony detection mechanism to decide as soon as possible during periods of synchrony. From these two results, we derive the size of the minimal window of synchrony needed to solve set agreement. By relating synchronous, asynchronous and partially synchronous environments, our simulation technique is of independent interest. In particular, it allows us to obtain a new lower bound on the complexity of early deciding k-set agreement complementary to that of Gafni et al. (in SIAM J. Comput. 40(1):63-78, 2011), and to re-derive the combinatorial topology lower bound of Guerraoui et al. (in Theor. Comput. Sci. 410(6-7):570-580, 2009) in an algorithmic way.}, author = {Alistarh, Dan-Adrian and Gilbert, Seth and Guerraoui, Rachid and Travers, Corentin}, journal = {Algorithmica (New York)}, number = {1-2}, pages = {595 -- 629}, publisher = {Springer}, title = {{Of choices, failures and asynchrony: the many faces of set agreement}}, doi = {10.1007/s00453-011-9581-7}, volume = {62}, year = {2012}, }