Congratulation!   2016   NTU-­‐CTS   Best   Paper   Award   goes   to   LeCosPA  Students:  Hsu-­‐Wen  Chiang,  Yao-­‐Chieh  Hu,  and  Yu-­‐Hsiang  Lin;  Che-­‐Yu  Chen  wins  CTS  Student  Scholarship.                          

 

From  left  to  right:  Yu-­‐Hsiang  Lin,  Che-­‐Yu  Chen,  Prof.  Pisin  Chen,  Yao-­‐Chieh  Hu,  

and  Hsu-­‐Wen  Chiang.    

   LeCosPA   students   in   the   theory   group:  Che-­‐Yu   Chen,  Hsu-­‐Wen   Chiang,  Yao-­‐Chieh  Hu  and  Yu-­‐Hsiang  Lin  won  the  “2016  best  paper  award”  from  the  Center   for   Theoretical   Science,   National   Taiwan   University   (NTU-­‐CTS).   In  

addition,   Che-­‐Yu   Chen  was   also   awarded   the  NTU-­‐CTS   Student   Scholarship.   In  

the  afternoon  of  May  25th,  they  presented  their  research  to  the  audience  during  

the   award   ceremony.   It   is   a   new   record   that   so  many   students   from   LeCosPA  

won   the   NTU-­‐CTS   award.   We   wish   to   congratulate   these   students   for   their  

achievements,   and  we  hope   that   they  will   continue   to   contribute   to   theoretical  

physics   in   their   future,   better,   research.   Let   us   now   learn   more   about   their  

award-­‐winning  works!    

 

Che-­‐Yu   Chen’s   project   is   to   analyze   the  

cosmological   singularities   in  

Eddington-­‐inspired-­‐Born-­‐Infeld   (EiBI)  

theory   and   its   other   extensions.   The  

singularity   problem   is   one   of   the   most  

important   issues   since   the   proposal   of  

general   relativity.   This   is   especially   so  

after   observation   showed   that   the  

expansion   of   our   universe   is   currently  

accelerating,   since   various   forms   of  

cosmological  singularities  could  arise  due  

to   the   accelerating   expansion,   depending  

on   the   cosmological   models.   Many   modified   theories   of   gravity   have   been  

proposed  to  either  avoid  or  cure  these  various  singularities.  In  his  work,  Che-­‐Yu  

and   his   collaborators   found   that  most   of   these   unpleasant   singularities   can   be  

alleviated   in  a   class  of  modified  gravity   theory  known  as   the  EiBI   theory.  They  

also   discovered   some   interesting   cosmological   solutions   that   are   allowed   in   a  

generalized  version  of  EiBI  theory.    

 

 

Yu-­‐Hsiang   Lin’s   research   area   is   the  

cosmic   inflation,  which   is  a  key  period   in  

the   history   of   the   universe.   Inflation  

explains   how   the   very   beginning   of   the  

cosmos  -­‐-­‐  the  big  bang  –  could  evolve  into  

what   we   see   in   the   night   sky   in   the  

present   epoch   of   the   universe.   The  

properties   of   inflation   may   explain   the  

existence   and   distribution   of   galaxies,  

cosmic   microwave   background,   dark  

matter,   and   dark   energy.   His   analysis  

shows   that   the   large-­‐angle   spectrum   of  

the   cosmic   microwave   background  

indicates   the   existence   of   a   "super-­‐inflation"   era   at   the   beginning   of   inflation.  

This   type   of   initial   stage   is   not   predicted   by   the   standard   model   of   particle  

physics   and   general   relativity,   but   could   be   the   hint   of   the   quantum   effect   of  

gravity,  as  suggested  by  string  theory  or  loop  quantum  gravity.  

 

Hsu-­‐Wen  Chiang  &  Yao-­‐Chieh  Hu  introduced a new type of spacetime quantization

based on the spinorial description suggested by loop quantum gravity (LQG). Perhaps

somewhat surprisingly, their theory is based on a Spin(3,1) worldsheet action inspired

by string theory, a long time competitor of LQG as the right theory of quantum

gravity. Indeed, their proposal may in principle provide some link back to string

theory in general, connect to LQG in which SU(2) is suggested as the fundamental

symmetry, and potentially even serve as a Lorentzian spin network. Hsu-Wen and

Yao-Chieh also derived the generalized uncertainty principle and demonstrate the

holographic nature of their theory.

Acknowledgements:

 

Che-­‐Yu  Chen:  I'm  profoundly  honored  to  be  awarded  the  CTS  scholarship.  I  wish  

to   thank   Prof.   Pisin   Chen   and  Dr.  Mariam  Bouhmadi-­‐López,   for   their   kind   and  

patient   instructions.   I   also  want   to   thank  all   the  members  of  LeCosPA   for   their  

help  and  discussions.  

 

Yu-­‐Hsiang   Lin:   I   am  happy  and  honored   to   receive   the  prize.  Thank  you  Prof.  

Chen  and  many  people   from  Taiwan,   Japan,   and  US   for  helping  me   throughout  

the  process.   I   also   benefited  much   from   the   visit   to   Stanford  during  which   the  

work  was  carried  out.  

 

Yao-­‐Chieh  Hu:   I'm deeply grateful to my advisor Prof. Pisin Chen for his guidance,

support, and the various opportunities provided. I am also thankful to my collaborator

--- Hsu-Wen Chiang, who made a major contribution in our project, for his

stimulating discussions and brilliant ideas. It is almost impossible to describe how I

benefited from being a part this project. Prof. Chen and Hsu-Wen have significantly

influenced me with their styles of thinking about physics and doing research.

Hsu-­‐Wen  Chiang:   I feel honored to receive the CTS prize. I would like to thank my

advisor Prof. Chen and my collaborator Yao-Chieh Hu. I would also like to thank the

professors and fellows in NTU physics department and LeCosPA. Lastly I wish to

thank my father and mother for their very kind supports.