The rational classification of links of codimension >2

Fix an integer m and a multi-index p = (p_1, ..., p_r) of integers p_i < m-2. The set of links of codimension > 2, with multi-index p, E(p, m), is the set of smooth isotopy classes of smooth embeddings of the disjoint union of the p_i-spheres into the m-sphere. Haefliger showed that E(p, m) is a finitely generated abelian group with respect to embedded connected summation and computed its rank in the case of knots, i.e. r=1. For r > 1 and for restrictions on p the rank of this group can be computed using results of Haefliger or Nezhinsky. Our main result determines the rank of the group E(p, m) in general. In particular we determine precisely when E(p,m) is finite. We also accomplish these tasks for framed links. Our proofs are based on the Haefliger exact sequence for groups of links and the theory of Lie algebras.Comment: 16 page

DNA double helices for single molecule electronics

The combination of self-assembly and electronic properties as well as its true nanoscale dimensions make DNA a promising candidate for a building block of single molecule electronics. We argue that the intrinsic double helix conformation of the DNA strands provides a possibility to drive the electric current through the DNA by the perpendicular electric (gating) field. The transistor effect in the poly(G)-poly(C) synthetic DNA is demonstrated within a simple model approach. We put forward experimental setups to observe the predicted effect and discuss possible device applications of DNA. In particular, we propose a design of the single molecule analog of the Esaki diode.Comment: 4 pages, 4 figur

Spin-dependent pump current and noise in an adiabatic quantum pump based on domain walls in a magnetic nanowire

We study the pump current and noise properties in an adiabatically modulated magnetic nanowire with double domain walls (DW). The modulation is brought about by applying a slowly oscillating magnetic and electric fields with a controllable phase difference. The pumping mechanism resembles the case of the quantum dot pump with two-oscillating gates. The pump current, shot noise, and heat flow show peaks when the Fermi energy matches with the spin-split resonant levels localized between the DWs. The peak height of the pump current is an indicator for the lifetime of the spin-split quasistationary states between the DWs. For sharp DWs, the energy absorption from the oscillating fields results in side-band formations observable in the pump current. The pump noise carries information on the correlation properties between the nonequilibrium electrons and the quasi-holes created by the oscillating scatterer. The ratio between the pump shot noise and the heat flow serves as an indicator for quasi-particle correlation.Comment: 18 pages, 5 figure

Hakikat Politik Dinasti Dari Perspektif Filsafat Sangkan Paraning Dumadi Dalam Bingkai Pancasila

Sekalipun pemilihan umum baru akan berlangsung pada tahun 2024, dinamika politik di Indonesia telah mulai memanas sejak pertengahan tahun 2022. Puncaknya di tahun 2023, pada saat Gibran Rakabuming Raka mendapatkan ‘tiket’ dicalonkan sebagai wakil presiden melalui rangkaian prahara Mahkamah Konstitusi, yang diyakini oleh banyak orang sebagai proses politik dinasti. Makalah ini meninjau hakikat politik dinasti dengan menggunakan pendekatan filsafat masyarakat orang Jawa, yaitu ‘sangkan paraning dumadi’, yang salah satu maknanya adalah mengingatkan manusia tentang dari mana ia berasal dan ke mana dia akan kembali. Filsafat sangkan paraning dumadi hidup dalam nilai-nilai Pancasila yang merupakan hasil kristalisasi konsep, nilai, etika dan moral yang digali dari bangsa Indonesia yang majemuk. Hakikat politik dinasti itu adalah upaya melanggengkan politik kekuasaan, dengan menggunakan upaya neopatrimonialistik, dalam tangan sekelompok orang, yang merasa paling benar, paling adil, dan bahkan telah lupa akan makna hidup dan tujuannya. Politik dinasti jelas bertentangan dengan filsafat sangkan paraning dumadi yang hidup dalam nilai-nilai Pancasila, karena mengingkari Tuhan sebagai sumber, pusat alam semesta dan kehidupan, serta akhir dari segalanya. Politik dinasti dalam praktiknya tidak luput dari tindakan yang menghalalkan segala cara dalam upaya mencapai kedudukan dan kesenangan, sehingga tidak menghiraukan nilai-nilai Ketuhanan. Tidak salah jika dalam persepsi sebagian besar masyarakat, praktik politik dinasti adalah salah satu penyebab utama maraknya korupsi, karena lebih mementingkan politik daripada kepentingan rakyat

Effect of Cash Conversion Cycle, Firm Size, and Firm Age to Profitability

This study aims to provide empirical evidence about effect of cash conversion cycle, firm size, and firm age to profitability. This study uses a quantitative approach, data collection techniques using purposive sampling method. The population in this research is manufacturing companies listed in Indonesia Stock Exchange (BEI) in the period 2012-2014 with a total sample of 101 companies and a total of as many as 303 samples of whole observation observation. This study uses panel data regression. This study was conducted to analyze the effect of the cash conversion cycle, firm size and age of the company to profitability by manufacturing companies using panel data through eviews 7.0. Establishment of a model in this study there are three models, namely common effect, fixed effect model and random effect model. Selection of the best model there are three, namely chow test, Hausman test, and langrangge multiplier. The results showed that the variable cash conversion cycle, firm size, firm age and positive effect on the variable return on assets. Variable leverage as control variables have no effect on the variable return on assets

Non-adiabatic Current Excitation in Quantum Rings

We investigate the difference in the response of a one-dimensional semiconductor quantum ring and a finite-width ring to a strong and short-lived time-dependent perturbation in the THz regime. In both cases the persistent current is modified through a nonadiabatic change of the many-electron states of the system, but by different mechanisms in each case.Comment: LaTeX, 5 pages with 6 embedded postscript figures, submitted to 20th Nordic Semiconductor Meeting, Tampere (2003

Energy Requirement of Control: Comments on Szilard's Engine and Maxwell's Demon

In mathematical physical analyses of Szilard's engine and Maxwell's demon, a general assumption (explicit or implicit) is that one can neglect the energy needed for relocating the piston in Szilard's engine and for driving the trap door in Maxwell's demon. If this basic assumption is wrong, then the conclusions of a vast literature on the implications of the Second Law of Thermodynamics and of Landauer's erasure theorem are incorrect too. Our analyses of the fundamental information physical aspects of various type of control within Szilard's engine and Maxwell's demon indicate that the entropy production due to the necessary generation of information yield much greater energy dissipation than the energy Szilard's engine is able to produce even if all sources of dissipation in the rest of these demons (due to measurement, decision, memory, etc) are neglected.Comment: New, simpler and more fundamental approach utilizing the physical meaning of control-information and the related entropy production. Criticism of recent experiments adde

Detection of spin polarized currents in quantum point contacts via transverse electron focusing

It has been predicted recently that an electron beam can be polarized when it flows adiabatically through a quantum point contact in a system with spin-orbit interaction. Here, we show that a simple transverse electron focusing setup can be used to detect such polarized current. It uses the amplitude's asymmetry of the spin-split transverse electron focusing peak to extract information about the electron's spin polarization. On the other hand, and depending on the quantum point contact geometry, including this one-body effect can be important when using the focusing setup to study many-body effects in quantum point contacts.Comment: 5 pages, 5 figure