645 research outputs found
The SL(K+3,C) Symmetry of the Bosonic String Scattering Amplitudes
We discover that the exact string scattering amplitudes (SSA) of three
tachyons and one arbitrary string state, or the Lauricella SSA (LSSA), in the
26D open bosonic string theory can be expressed in terms of the basis functions
in the infinite dimensional representation space of the SL(K+3,C) group. In
addition, we find that the K+2 recurrence relations among the LSSA discovered
by the present authors previously can be used to reproduce the Cartan
subalgebra and simple root system of the SL(K+3,C) group with rank K+2. As a
result, the SL(K+3,C) group can be used to solve all the LSSA and express them
in terms of one amplitude. As an application in the hard scattering limit, the
SL(K+3,C) group can be used to directly prove Gross conjecture [1-3], which was
previously corrected and proved by the method of decoupling of zero norm states
[4-10].Comment: 19 pages, no figure. v2: 20 pages, typos corrected and Eqs. added.
v3: 24 pages, Examples in sec. II added,"Discussion" added, to be published
in Nucl.Phys.
String Scattering Amplitudes and Deformed Cubic String Field Theory
We study string scattering amplitudes by using the deformed cubic string
field theory which is equivalent to the string field theory in the proper-time
gauge. The four-string scattering amplitudes with three tachyons and an
arbitrary string state are calculated. The string field theory yields the
string scattering amplitudes evaluated on the world sheet of string scattering
whereas the coventional method, based on the first quantized theory brings us
the string scattering amplitudes defined on the upper half plane. For the
highest spin states, generated by the primary operators, both calculations are
in perfect agreement. In this case, the string scattering amplitudes are
invariant under the conformal transformation, which maps the string world sheet
onto the upper half plane. If the external string states are general massive
states, generated by non-primary field operators, we need to take into account
carefully the conformal transformation between the world sheet and the upper
half plane. We show by an explicit calculation that the string scattering
amplitudes calculated by using the deformed cubic string field theory transform
into those of the first quantized theory on the upper half plane by the
conformal transformation, generated by the Schwarz-Christoffel mapping.Comment: 12 pages, 2 figures, references adde
Solving Lauricella String Scattering Amplitudes through Recurrence Relations
We show that there exist infinite number of recurrence relations valid for
all energies among the open bosonic string scattering amplitudes (SSA) of three
tachyons and one arbitrary string state, or the Lauricella SSA. Moreover, these
infinite number of recurrence relations can be used to solve all the Lauricella
SSA and express them in terms of one single four tachyon amplitude. These
results extend the solvability of SSA at the high energy, fixed angle
scattering limit and those at the Regge scattering limit discovered previously.Comment: 19 pages. v2: Fig.1 adde
Cultural Identity and the Making of Modern Taiwanese Painting During the Japanese Colonial Period (1895-1945).
This dissertation addresses the multifaceted aspects of cultural identity as expressed in modern Taiwanese paintings during the Japanese colonial era, from 1895 to 1945. Under Japanese rule, Taiwan was united for the first time by a single official language and a standardized Western-influenced education system. In those circumstances, Taiwan underwent fast-paced modernization that gave rise to challenging new cultural forms and ideologies, and provided space for the gradual development of a new sense of personal and cultural identity.
The present study reveals that rather than manifesting a uniform cultural identity or ideological orientation, Western-style paintings of the period demonstrate ambiguity and hybridity, with oscillation between Chinese, Japanese and Western outlooks and signs of an emergent Taiwanese consciousness characterized by a cosmopolitan spirit rooted in love for the land.
Chapter One outlines Taiwan’s history and Sino-centric cultural development before the Japanese colonial era. Chapter Two discusses the difficulties confronting aspiring Taiwanese artists during Japanese rule and examines popular new themes, such as the artist’s studio, the self-portrait and the family portrait, which shed light on the fluid construction of new cultural identities. Chapter Three examines artworks and writings by leading expatriate Japanese painters and commentators touching on the question of Taiwan’s cultural distinctiveness. Chapter Four addresses the emergence among the Taiwanese of an ever-maturing consciousness of Taiwan and themselves as a distinctive, integral whole in relation to the colonial mother country, the ancestral motherland and the world.
Taiwanese painters of the Japanese colonial period both mirrored and contributed to trends in the evolution of the island’s cultural identity. Through a careful analysis of form and content, this dissertation concludes that while the paintings are less pointed and discursively revealing than were contemporaneous Taiwanese literary works, they provide invaluable testimony to the multivalent complexity of the period’s cross-cultural dynamics and to the individual artists’ search for a vision of Taiwan, Taiwanese-ness, and a broader humanity that lies beyond.Ph.D.History of ArtUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/61650/1/jyl_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/61650/2/jyl_3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/61650/3/jyl_2.pd
The symmetry of string scatterings from D-branes
By using the solvability of Lauricella function with nonpositive
integer , we show that each scattering or decay process of string
and D-brane states at \textit{arbitrary} mass levels can be expressed in terms
of a single Lauricella function. This result extends the previous exact
symmetry of tree-level open bosonic string theory to
include the D-brane.Comment: 15 pages, no figure. arXiv admin note: text overlap with
arXiv:2108.06326. v2: 18 pages. Final in Nucl.Phys.
Stringy scaling of n-point Regge string scattering amplitudes
We discover a stringy scaling behavior for a class of n-point Regge string
scattering amplitudes (RSSA). The number of independent kinematics variables is
found to be reduced by dim M.Comment: 33 pages, 1 figur
Recent developments of the Lauricella string scattering amplitudes and their exact SL(K+3,C) Symmetry
In this review we propose a new perspective to demonstrate Gross conjecture
on high energy symmetry of string theory. We review the construction of the
exact string scattering amplitudes (SSA) of three tachyons and one arbitrary
string state, or the Lauricella SSA (LSSA), in the 26D open bosonic string
theory. These LSSA form an infinite dimensional representation of the SL(K+3,C)
group. Moreover, we show that the SL(K+3,C) group can be used to solve all the
LSSA and express them in terms of one amplitude. As an application in the hard
scattering limit, the LSSA can be used to directly prove Gross conjecture which
was previously corrected and proved by the method of decoupling of zero norm
states (ZNS). Finally, the exact LSSA can be used to rederive the recurrence
relations of SSA in the Regge scattering limit with associated SL(5,C) symmetry
and the extended recurrence relations (including the mass and spin dependent
string BCJ relations) in the nonrelativistic scattering limit with associated
SL(4,C) symmetry discovered recently.Comment: 54 pages, 1 figure, minor modification, references added. arXiv admin
note: text overlap with arXiv:1806.0503
Stringy scaling of n-point hard string scattering amplitudes
Motivated by the recent calculation of the SL(K+3,C) symmetry of n-point
Lauricella string scattering amplitudes (SSA) of open bosonic string theory, we
calculate ratios of the solvable infinite linear relations of arbitrary n-point
hard SSA (HSSA). We discover a general stringy scaling behavior for all n-point
HSSA to all string loop orders. For the special case of n=4, the stringy
scaling behavior reduces to the infinite linear relations and constant ratios
among HSSA conjectured by Gross [8] and later corrected and calculated by the
method of decoupling of zero-norm states [11].Comment: 12 pages, no figure. v2: 13 pages, improve calculation in section III
without changing result
The initial abundance and distribution of 92Nb in the Solar System
Niobium-92 is an extinct proton-rich nuclide, which decays to 92Zr with a
half-life of 37 Ma. This radionuclide potentially offers a unique opportunity
to determine the timescales of early Solar System processes and the site(s) of
nucleosynthesis for p-nuclei, once its initial abundance and distribution in
the Solar System are well established. Here we present internal Nb-Zr isochrons
for three basaltic achondrites with known U-Pb ages: the angrite NWA 4590, the
eucrite Agoult, and the ungrouped achondrite Ibitira. Our results show that the
relative Nb-Zr isochron ages of the three meteorites are consistent with the
time intervals obtained from the Pb-Pb chronometer for pyroxene and
plagioclase, indicating that 92Nb was homogeneously distributed among their
source regions. The Nb-Zr and Pb-Pb data for NWA 4590 yield the most reliable
and precise reference point for anchoring the Nb-Zr chronometer to the absolute
timescale: an initial 92Nb/93Nb ratio of at
Ma, which corresponds to a 92Nb/93Nb ratio of at the time of the Solar System formation. On the basis of this
new initial ratio, we demonstrate the capability of the Nb-Zr chronometer to
date early Solar System objects including troilite and rutile, such as iron and
stony-iron meteorites. Furthermore, we estimate a nucleosynthetic production
ratio of 92Nb to the p-nucleus 92Mo between 0.0015 and 0.035. This production
ratio, together with the solar abundances of other p-nuclei with similar
masses, can be best explained if these light p-nuclei were primarily
synthesized by photodisintegration reactions in Type Ia supernovae.Comment: Accepted to Earth and Planetary Science Letter
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