5,138 research outputs found
Localized Thermal States
It is believed that thermalization in closed systems of interacting particles
can occur only when the eigenstates are fully delocalized and chaotic in the
preferential (unperturbed) basis of the total Hamiltonian. Here we demonstrate
that at variance with this common belief the typical situation in the systems
with two-body inter-particle interaction is much more complicated and allows to
treat as thermal even eigenstates that are not fully delocalized. Using a
semi-analytical approach we establish the conditions for the emergence of such
thermal states in a model of randomly interacting bosons. Our numerical data
show an excellent correspondence with the predicted properties of {\it
localized thermal eigenstates}.Comment: Proceedings of the 5th Conference on Nuclei and Mesoscopic Physics,
NMP17, East Lansing (USA
Timescales in the quench dynamics of many-body quantum systems: Participation ratio vs out-of-time ordered correlator
We study quench dynamics in the many-body Hilbert space using two isolated
systems with a finite number of interacting particles: a paradigmatic model of
randomly interacting bosons and a dynamical (clean) model of interacting
spins-. For both systems in the region of strong quantum chaos, the number
of components of the evolving wave function, defined through the number of
principal components (or participation ratio), was recently found to
increase exponentially fast in time [Phys. Rev. E 99, 010101R (2019)]. Here, we
ask whether the out-of-time ordered correlator (OTOC), which is nowadays widely
used to quantify instability in quantum systems, can manifest analogous
time-dependence. We show that can be formally expressed as the inverse
of the sum of all OTOC's for projection operators. While none of the individual
projection-OTOC's shows an exponential behavior, their sum decreases
exponentially fast in time. The comparison between the behavior of the OTOC
with that of the helps us better understand wave packet dynamics in
the many-body Hilbert space, in close connection with the problems of
thermalization and information scrambling.Comment: 11 pages, 7 figure
Steiner's formula in the Heisenberg group
Steiner's tube formula states that the volume of an ∈-neighborhood of a smooth regular domain in ℝn is a polynomial of degree n in the variable ∈ whose coefficients are curvature integrals (also called quermassintegrals). We prove a similar result in the sub-Riemannian setting of the first Heisenberg group. In contrast to the Euclidean setting, we find that the volume of an ∈-neighborhood with respect to the Heisenberg metric is an analytic function of ∈ that is generally not a polynomial. The coefficients of the series expansion can be explicitly written in terms of integrals of iteratively defined canonical polynomials of just five curvature terms
On The Dynamic Programming Approach To Incentive Constraint Problems
In this paper we study a class of infinite horizon optimal control problems with incentive constraints in the discrete time case. More specifically, we establish suffcient conditions under which the value function associated to such problems satisfies the Dynamic Programming Principle.In this paper we study a class of infinite horizon optimal control problems with incentive constraints in the discrete time case. More specifically, we establish suffcient conditions under which the value function associated to such problems satisfies the Dynamic Programming Principle.Non-Refereed Working Papers / of national relevance onl
On the ordeal of quinolone preparation via cyclisation of aryl-enamines; synthesis and structure of ethyl 6-methyl-7-iodo-4-(3-iodo-4-methylphenoxy)-quinoline-3-carboxylate
Recent studies directed to the design of compounds targeting the bc(1) protein complex of Plasmodium falciparum, the parasite responsible for most lethal cases of malaria, identified quinolones (4-oxo-quinolines) with low nanomolar inhibitory activity against both the enzyme and infected erythrocytes. The 4-oxo-quinoline 3-ester chemotype emerged as a possible source of potent bc(1) inhibitors, prompting us to expand the library of available analogs for SAR studies and subsequent lead optimization. We now report the synthesis and structural characterization of unexpected ethyl 6-methyl-7-iodo-4-(3-iodo-4-methylphenoxy)quinoline-3-carboxylate, a 4-aryloxy-quinoline 3-ester formed during attempted preparation of 6-methyl-7-iodo-4-oxo-quinoline-3-carboxylate (4-oxo-quinoline 3-ester). We propose that the 4-aryloxy-quinoline 3-ester derives from 6-methyl-7-iodo-4-hydroxy-quinoline-3-carboxylate (4-hydroxy-quinoline 3-ester), the enol form of 6-methyl-7-iodo-4-oxo-quinoline-3-carboxylate. Formation of the 4-aryloxy-quinoline 3-ester confirms the impact of quinolone/hydroxyquinoline tautomerism, both on the efficiency of synthetic routes to quinolones and on pharmacologic profiles. Tautomers exhibit different cLogP values and interact differently with the enzyme active site. A structural investigation of 6-methyl-7-iodo-4-oxo-quinoline-3-carboxylate and 6-methyl-7-iodo-4-hydroxy-quinoline-3-carboxylate, using matrix isolation coupled to FTIR spectroscopy and theoretical calculations, revealed that the lowest energy conformers of 6-methyl-7-iodo-4-hydroxy-quinoline-3-carboxylate, lower in energy than their most stable 4-oxo-quinoline tautomer by about 27 kJ mol(-1), are solely present in the matrix, while the most stable 4-oxo-quinoline tautomer is solely present in the crystalline phase.Fundacao para a Ciencia e Tecnologia (FCT - Portugal) [UID/Multi/04326/2013]; QREN-COMPETE-UE; CCMAR; FCT [SFRH/BD/81821/2011, RECI/BBB-BQB/0230/2012, UI0313/QUI/2013, UID/FIS/04564/2016]; FEDER/COMPETE-UE; [PTDC/QEQ-QFI/3284/2014 - POCI-01-0145-FEDER-016617]info:eu-repo/semantics/publishedVersio
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