Mosses new to Hong Kong (1)

Ten moss species - Garkea flexuosa (Griffith) Marg. & Nork., Campylopus laxitextus Lac., Fissidens dubius P. Beauv., Fissidens ceylonensis Dozy & Molk, Fissidens maceratus Mitt., Philonotis thwaitesii Mitt., Isopterygium minutirameum (C. Muell.)Jaeg., Homalia trichomanoides (Hedw.) B.S.G., Pogonatum neesii (C. Muell.) Dozyand Polytrichum formosum Hedw. are reported new to Hong Kong. Among them, five are new to Guangdong Province of China

Mosses new to Hong Kong (4)

Sixteen moss species - Eurhynchium asperisetum (C. Muell.) Tak.; Rhynchostegium pallidifolium (Mitt.) Jaeg.; Bryum argenteum Hedw.; Bryum caespiticium Hedw.; Bryum capillare Hedw.; Platyhynidium riarioides (Hedw.) Dix.; Dicranella varia (Hedw.) Schimp.;Entodon virudulus Card.; Fissidens strictulus C. Muell.; Ectropothecium obtusulum (Card.) Iwats.; Caduciella guangdongensis Enroth.; Plagiomnium cuspidatum (Hedw.) T. Kop.; Plagiomnium vesicatum (Besch.) T. Kop.; Pyrrhobryum spiniforme (Hedw.) Mitt., Taxithelium nepalense (Schwaegr.) Broth. and Claopodium aciculum (Broth.) Broth. are reported new to Hong Kong. Among them, four are new to Guangdong Province of China

On Euler characteristics for large Kronecker quivers

We study Euler characteristics of moduli spaces of stable representations of m-Kronecker quivers for m>>0.Comment: submitted versio

On stability manifolds of Calabi-Yau surfaces

We prove some general statements on stability conditions of Calabi-Yau surfaces and discuss the stability manifold of the cotangent bundle of P^1. Our primary interest is in spherical objects.Comment: 15 pages, revised in responce to referee's comments, to appear in IMR

Quintic periods and stability conditions via homological mirror symmetry

For the Fermat Calabi-Yau threefold and the theory of stability conditions [Bri07], there have been two mathematical aims given by physical reasoning. One is that we should define stability conditions by central charges of quintic periods [Hos04,Kon12,KonSoi13], which extend the Gamma class [KKP,Iri09,Iri11]. The other is that for well-motivated stability conditions on a derived Fukaya-type category, each stable object should be a Lagrangian [ThoYau]. We answer affirmatively to these aims with the simplest homological mirror symmetry (HMS for short) of the Fermat Calabi-Yau threefold [Oka09,FutUed] and stability conditions of Bridgeland type, which we introduce. With HMS, we naturally obtain stability conditions of Bridgeland type by the monodromy around the Gepner point. As consequences, we obtain bases of quintic periods and the mirror map [CdGP] categorically, wall-crossings by quintic periods, and a quasimodular form [KanZag] attached to quintic periods by motivic Donaldson-Thomas invariants [KonSoi08]. The quasimodular form is of the quantum dilogarithm and of a mock modular form [Zag06].Comment: 20 pages, 5 figures, a substantial revision, Comments are welcom