326 research outputs found
A Networks-Science Investigation into the Epic Poems of Ossian
In 1760 James Macpherson published the first volume of a series of epic poems
which he claimed to have translated into English from ancient Scottish-Gaelic
sources. The poems, which purported to have been composed by a third-century
bard named Ossian, quickly achieved wide international acclaim. They invited
comparisons with major works of the epic tradition, including Homer's Iliad and
Odyssey, and effected a profound influence on the emergent Romantic period in
literature and the arts. However, the work also provoked one of the most famous
literary controversies of all time, colouring the reception of the poetry to
this day. The authenticity of the poems was questioned by some scholars, while
others protested that they misappropriated material from Irish mythological
sources. Recent years have seen a growing critical interest in Ossian,
initiated by revisionist and counter-revisionist scholarship and by the
two-hundred-and-fiftieth anniversary of the first collected edition of the
poems in 1765. Here we investigate Ossian from a networks-science point of
view. We compare the connectivity structures underlying the societies described
in the Ossianic narratives with those of ancient Greek and Irish sources.
Despite attempts, from the outset, to position Ossian alongside the Homeric
epics and to distance it from Irish sources, our results indicate significant
network-structural differences between Macpherson's text and those of Homer.
They also show a strong similarity between Ossianic networks and those of the
narratives known as Acallam na Sen\'orach (Colloquy of the Ancients) from the
Fenian Cycle of Irish mythology.Comment: Accepted for publication in Advances in Complex system
Membrane amplitude and triaxial stress in twisted bilayer graphene deciphered using first-principles directed elasticity theory and scanning tunneling microscopy
Twisted graphene layers produce a moir\'e pattern (MP) structure with a
predetermined wavelength for given twist angle. However, predicting the
membrane corrugation amplitude for any angle other than pure AB-stacked or
AA-stacked graphene is impossible using first-principles density functional
theory (DFT) due to the large supercell. Here, within elasticity theory we
define the MP structure as the minimum energy configuration, thereby leaving
the height amplitude as the only unknown parameter. The latter is determined
from DFT calculations for AB and AA stacked bilayer graphene in order to
eliminate all fitting parameters. Excellent agreement with scanning tunneling
microscopy (STM) results across multiple substrates is reported as function of
twist angle.Comment: to appear in Phys. Rev.
Polarization selection rules for inter-Landau level transitions in epitaxial graphene revealed by infrared optical Hall effect
We report on polarization selection rules of inter-Landau level transitions
using reflection-type optical Hall effect measurements from 600 to 4000 cm-1 on
epitaxial graphene grown by thermal decomposition of silicon carbide. We
observe symmetric and anti-symmetric signatures in our data due to polarization
preserving and polarization mixing inter-Landau level transitions,
respectively. From field-dependent measurements we identify that transitions in
decoupled graphene mono-layers are governed by polarization mixing selection
rules, whereas transitions in coupled graphene mono-layers are governed by
polarization preserving selection rules. The selection rules may find
explanation by different coupling mechanisms of inter-Landau level transitions
with free charge carrier magneto-optic plasma oscillations
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