192 research outputs found
Issues Arises after Implementation of GST in India
After independence of India the biggest reform of indirect taxation is GST It was supposed to be implemented from April 2010 but due to economic and political reasons it was long pending After implantation of GST on 1st July 2017 there are lot of issues arises in the ground level This paper is highlighting the challenges faced by Government of India after implementatio
Study of Sunspot Penumbra to Umbra Area Ratio using Kodaikanal White-light Digitized Data
We study the long-term behaviour of sunspot penumbra to umbra area ratio by
analyzing the recently digitized Kodaikanal white-light data (1923-2011). We
implement an automatic umbra extraction method and compute the ratio over eight
solar cycles (Cycles 16-23). Although the average ratio doesn't show any
variation with spot latitudes, cycle phases and strengths, it increases from
5.5 to 6 as the sunspot size increases from 100 hem to 2000 hem.
Interestingly, our analysis also reveals that this ratio for smaller sunspots
(area 100 hem) does not have any long-term systematic trend which was
earlier reported from the Royal Observatory, Greenwich (RGO) photographic
results. To verify the same, we apply our automated extraction technique on
Solar and Heliospheric Observatory (SOHO)/Michelson Doppler Imager (MDI)
continuum images (1996-2010). Results from this data not only confirm our
previous findings, but also show the robustness of our analysis method.Comment: Accepted for publication in Solar Physics (15 pages, 10 figures
MHV Gluon Scattering Amplitudes from Celestial Current Algebras
We show that the Mellin transform of an -point tree level MHV gluon
scattering amplitude, also known as the celestial amplitude in pure Yang-Mills
theory, satisfies a system of linear first order partial differential
equations corresponding to positive helicity gluons. Although these
equations closely resemble Knizhnik-Zamolodchikov equations for current
algebra there is also an additional "correction" term coming from the
subleading soft gluon current algebra. These equations can be used to compute
the leading term in the gluon-gluon OPE on the celestial sphere. Similar
equations can also be written down for the momentum space tree level MHV
scattering amplitudes. We also propose a way to deal with the non closure of
subleading current algebra generators under commutation. This is then used to
compute some subleading terms in the mixed helicity gluon OPE and our results
match with those obtained from an explicit calculation using the Mellin MHV
amplitude.Comment: 26+23 Pages, Latex, Typo corrected, Some discussions on subleading
soft gluon symmetry is changed, Results unchange
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