484 research outputs found
Finite TYCZ expansions and cscK metrics
Let be a Kaehler manifold whose associated Kaehler form is
integral and let be a quantization hermitian
line bundle. In this paper we study those Kaehler manifolds admitting
a finite TYCZ expansion. We show that if the TYCZ expansion is finite then
is indeed a polynomial in of degree , , and the
log-term of the Szeg\"{o} kernel of the disc bundle vanishes
(where is the dual bundle of ). Moreover, we provide a complete
classification of the Kaehler manifolds admitting finite TYCZ expansion either
when is a complex curve or when is a complex surface with a cscK metric
which admits a radial Kaehler potential
Symplectic geometry of Cartan–Hartogs domains
This paper studies the geometry of Cartan–Hartogs domains from the symplectic point of view. Inspired by duality between compact and noncompact Hermitian symmetric spaces, we construct a dual counterpart of Cartan–Hartogs domains and give explicit expression of global Darboux coordinates for both Cartan–Hartogs domains and their dual. Further, we compute their symplectic capacity and show that a Cartan–Hartogs domain admits a symplectic duality if and only if it reduces to be a complex hyperbolic space
Immersions of Sasaki–Ricci solitons into homogeneous Sasakian manifolds
We discuss local Sasakian immersion of Sasaki-Ricci solitons (SRS) into fiber products of homogeneous Sasakian manifolds. In particular, we prove that SRS locally induced by alarge class of fiber products of homogeneous Sasakian manifolds are, in fact, eta-Einstein. The results are stronger for immersions into Sasakian space forms. Moreover, we show an example of a Kähler-Ricci soliton on C^n which admits no local holomorphic isometry into products of homogeneous bounded domains with flat Kähler manifolds and generalized flag manifolds
Minimal symplectic atlases of Hermitian symmetric spaces
In this paper we estimate the minimal number of Darboux charts needed to cover a Hermitian symmetric space of compact type M in terms of the degree of their embeddings in CPN. The proof is based on the recent work of Rudyak and Schlenk (Commun Contemp Math 9(6):811–855, 2007) and on the symplectic geometry tool developed by the first author in collaboration with Loi et al. (J Sympl Geom, 2014). As application we compute this number for a large class of Hermitian symmetric spaces of compact type
Vibrational origin of the fast relaxation processes in molecular glass-formers
We study the interaction of the relaxation processes with the density
fluctuations by molecular dynamics simulation of a flexible molecule model for
o-terphenyl (oTP) in the liquid and supercooled phases. We find evidence,
besides the structural relaxation, of a secondary vibrational relaxation whose
characteristic time, few ps, is slightly temperature dependent. This i)
confirms the result by Monaco et al. [Phys. Rev, E 62, 7595 (2000)] of the
vibrational nature of the fast relaxation observed in Brillouin Light
Scattering (BLS) experiments in oTP; and ii) poses a caveat on the
interpretation of the BLS spectra of molecular systems in terms of a purely
center of mass dynamics.Comment: RevTeX, 5 pages, 4 eps figure
Equilibrium cluster phases and low-density arrested disordered states: The role of short-range attraction and long-range repulsion
We study a model in which particles interact with short-ranged attractive and
long-ranged repulsive interactions, in an attempt to model the equilibrium
cluster phase recently discovered in sterically stabilized colloidal systems in
the presence of depletion interactions. At low packing fraction particles form
stable equilibrium clusters which act as building blocks of a cluster fluid. We
study the possibility that cluster fluids generate a low-density disordered
arrested phase, a gel, via a glass transition driven by the repulsive
interaction. In this model the gel formation is formally described with the
same physics of the glass formation.Comment: RevTeX4, 4 pages, 4 eps figure
Equilibrium and out of equilibrium thermodynamics in supercooled liquids and glasses
We review the inherent structure thermodynamical formalism and the
formulation of an equation of state for liquids in equilibrium based on the
(volume) derivatives of the statistical properties of the potential energy
surface. We also show that, under the hypothesis that during aging the system
explores states associated to equilibrium configurations, it is possible to
generalize the proposed equation of state to out-of-equilibrium conditions. The
proposed formulation is based on the introduction of one additional parameter
which, in the chosen thermodynamic formalism, can be chosen as the local minima
where the slowly relaxing out-of-equilibrium liquid is trapped.Comment: 7 pages, 4 eps figure
Kovacs effects in an aging molecular liquid
We study by means of molecular dynamics simulations the aging behavior of a
molecular model of ortho-terphenyl. We find evidence of a a non-monotonic
evolution of the volume during an isothermal-isobaric equilibration process, a
phenomenon known in polymeric systems as Kovacs effect. We characterize this
phenomenology in terms of landscape properties, providing evidence that, far
from equilibrium, the system explores region of the potential energy landscape
distinct from the one explored in thermal equilibrium. We discuss the relevance
of our findings for the present understanding of the thermodynamics of the
glass state.Comment: RevTeX 4, 4 pages, 5 eps figure
A Simple Theory of Condensation
A simple assumption of an emergence in gas of small atomic clusters
consisting of particles each, leads to a phase separation (first order
transition). It reveals itself by an emergence of ``forbidden'' density range
starting at a certain temperature. Defining this latter value as the critical
temperature predicts existence of an interval with anomalous heat capacity
behaviour . The value suggested in literature
yields the heat capacity exponent .Comment: 9 pages, 1 figur
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