173 research outputs found
Ward Identities and High-energy Scattering Amplitudes in String Theory
High-energy limit of stringy Ward identities derived from the decoupling of
two types of zero-norm states in the old covariant first quantized (OCFQ)
spectrum of open bosonic string are used to check the consistency of saddle
point calculations of high energy scattering amplitudes of Gross and Mende and
Gross and Manes. Some inconsistencies of their saddle point calculations are
found even for the string-tree scattering amplitudes of the excited string
states. We discuss and calculate the missing terms of the calculation by those
authors to recover the stringy Ward identities. In addition, based on the
tree-level stringy Ward identities, we give the proof of a general formula,
which was proposed previously, of all high energy four-point string-tree
amplitudes of arbitrary particles in the string spectrum. In this formula all
such scattering amplitudes are expressed in terms of those of tachyons as
conjectured by Gross. The formula is extremely simple which manifestly
demonstrates the universal high energy behavior of the interactions among all
string states.Comment: 1 typo, to appear in Nucl. Phys.
Zero-norm states and stringy symmetries
We identify spacetime symmetry charges of 26D open bosonic string theory from
an infinite number of zero-norm states (ZNS) with arbitrary high spin in the
old covariant first quantized string spectrum. We give various evidences to
support this identification. These include massive sigma-model calculation,
Witten string field theory calculation, 2D string theory calculation and, most
importantly, three methods of high-energy stringy scattering amplitude
calculations. The last calculations explicitly prove Gross's conjectures in
1988 on high energy symmetry of string theory.Comment: 6 pages. Talks presented by Jen-Chi Lee at XXVIII Spanish Relativity
Meeting (ERE2005),"A Century of Relativity Physics",Oviedo,Spain,6-10 Sep
2005 and "4th Meeting on constrained Dynamics and Quantum Gravity",Cala
Gonone,Sardinia,Italy,12-16 Sep 2005. To appear in the Journal of Physics:
Conference Serie
High-energy zero-norm states and symmetries of string theory
High-energy limit of zero-norm states (HZNS) in the old covariant first
quantized (OCFQ) spectrum of the 26D open bosonic string, together with the
assumption of a smooth behavior of string theory in this limit, are used to
derive infinitely many linear relations among the leading high-energy, fixed
angle behavior of four point functions of different string states. As a result,
ratios among all high-energy scattering amplitudes of four arbitrary string
states can be calculated algebraically and the leading order amplitudes can be
expressed in terms of that of four tachyons as conjectured by Gross in 1988. A
dual calculation can also be performed and equivalent results are obtained by
taking the high-energy limit of Virasoro constraints. Finally, as a consistent
sample calculation, we compute all high-energy scattering amplitudes of three
tachyons and one massive state at the leading order by saddle-point
approximation to justify our results.Comment: 10 pages, no figure, modifications of text and reference
The digital defence against cyberbullying: A systematic review of tech-based approaches
Cyberbullying, which has been exacerbated by the widespread use of smartphones and the increasing stress associated with the pandemic, needs the promotion of positive online behaviour, cyberbullying awareness, and victim support. The PRISMA technique is used in this review to identify effective preventative tools and intervention options. Eleven studies met our inclusion criteria and were selected for review. A quality assessment was conducted. Upon thorough evaluation of the included studies, the intervention data was compiled in a narrative format. Using thematic analysis, we explored the effectiveness of technological interventions for preventing cyberbullying comprehensively. Technology-driven strategies for identifying and combating cyberbullying in educational settings, such as language-specific cyberbullying detection tools, IRCB programmes for empowering teenagers, and technologies such as CREEP Semantic Technology and CREEP Virtual Coach, have showed potential. TIPIP and the #WIIWY movement have also assisted to raise awareness and educate people about cyberbullying. However, more research is required to design targeted interventions that address varied demographics and circumstances, while including parents and taking the target audience’s age into account remains critical for effective technology-driven educational interventions and digital advocacy
The prediction of Alzheimer’s disease through multi-trait genetic modeling
To better capture the polygenic architecture of Alzheimer’s disease (AD), we developed a joint genetic score, MetaGRS. We incorporated genetic variants for AD and 24 other traits from two independent cohorts, NACC (n = 3,174, training set) and UPitt (n = 2,053, validation set). One standard deviation increase in the MetaGRS is associated with about 57% increase in the AD risk [hazard ratio (HR) = 1.577, p = 7.17 E-56], showing little difference from the HR for AD GRS alone (HR = 1.579, p = 1.20E-56), suggesting similar utility of both models. We also conducted APOE-stratified analyses to assess the role of the e4 allele on risk prediction. Similar to that of the combined model, our stratified results did not show a considerable improvement of the MetaGRS. Our study showed that the prediction power of the MetaGRS significantly outperformed that of the reference model without any genetic information, but was effectively equivalent to the prediction power of the AD GRS
The digital defence against cyberbullying: A systematic review of tech-based approaches
Cyberbullying, which has been exacerbated by the widespread use of smartphones and the increasing stress associated with the pandemic, needs the promotion of positive online behaviour, cyberbullying awareness, and victim support. The PRISMA technique is used in this review to identify effective preventative tools and intervention options. Eleven studies met our inclusion criteria and were selected for review. A quality assessment was conducted. Upon thorough evaluation of the included studies, the intervention data was compiled in a narrative format. Using thematic analysis, we explored the effectiveness of technological interventions for preventing cyberbullying comprehensively. Technology-driven strategies for identifying and combating cyberbullying in educational settings, such as language-specific cyberbullying detection tools, IRCB programmes for empowering teenagers, and technologies such as CREEP Semantic Technology and CREEP Virtual Coach, have showed potential. TIPIP and the #WIIWY movement have also assisted to raise awareness and educate people about cyberbullying. However, more research is required to design targeted interventions that address varied demographics and circumstances, while including parents and taking the target audience’s age into account remains critical for effective technology-driven educational interventions and digital advocacy
Bullying, Eating Disorders and Coping Strategies among Adolescents in Malaysia
Understanding how bullying leads to eating disorders can help develop effective intervention strategies. This phenomenological study examines the relationship between bullying and coping strategies Malaysian adolescents diagnosed with eating disorders use. Using the snowball sampling technique, 12 Kuala Lumpur participants, six females and six males aged 10 to 19, responded to interview questions based on the literature reviews, theories, and a published questionnaire. By using thematic analysis, the researcher found out that all 12 participants with EDs were bullied about their weight or size. Most of the bullying and teasing were verbal or via online platforms. The findings suggest that bullying can be a significant cause of the development of eating disorders among adolescents in Malaysia. Proper coping strategies can be essential in overcoming the trauma of being bullied and treating eating disorders
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