scholarly journals Normal ordering and boundary conditions in open bosonic strings

2005 ◽  
Vol 46 (6) ◽  
pp. 062302 ◽  
Author(s):  
Nelson R. F. Braga ◽  
Hector L. Carrion ◽  
Cresus F. L. Godinho
2006 ◽  
Vol 74 (10) ◽  
Author(s):  
Biswajit Chakraborty ◽  
Sunandan Gangopadhyay ◽  
Arindam Ghosh Hazra

2006 ◽  
Vol 638 (2-3) ◽  
pp. 272-274 ◽  
Author(s):  
Nelson R.F. Braga ◽  
Hector L. Carrion ◽  
Cresus F.L. Godinho

1987 ◽  
Vol 02 (03) ◽  
pp. 729-738 ◽  
Author(s):  
G. CRISTOFANO ◽  
G. MAIELLA ◽  
R. MUSTO ◽  
F. NICODEMI ◽  
R. PETTORINO

We study the consequences of requiring twisted boundary conditions on [Formula: see text] coordinates of the 26-D bosonic string. In the context of a heterotic model when [Formula: see text] we are led to the tachyonand anomaly-free O (16) ⊗ O (16) model which has been recently discussed in the literature.


Author(s):  
Stjepan Meljanac ◽  
◽  
Rina Štrajn ◽  
◽  
◽  
...  

We consider a class of exponentials in the Weyl-Heisenberg algebra with exponents of type at most linear in coordinates and arbitrary functions of momenta. They are expressed in terms of normal ordering where coordinates stand to the left from momenta. Exponents appearing in normal ordered form satisfy differential equations with boundary conditions that could be solved perturbatively order by order. Two propositions are presented for the Weyl-Heisenberg algebra in 2 dimensions and their generalizations in higher dimensions. These results can be applied to arbitrary noncommutative spaces for construction of star products, coproducts of momenta and twist operators. They can also be related to the BCH formula.


2009 ◽  
Vol 24 (03) ◽  
pp. 239-249
Author(s):  
ZHEN-BIN CAO ◽  
YI-SHI DUAN

Generally, in the presence of an antisymmetric tensor background field, the open string moving with mixed Neumann and Dirichlet boundary conditions will make the spacetime coordinates noncommutative. In this paper, comparing to the flat and static D-brane case studied in the literature, we first generalize the D-branes to be dynamical. And then by using the Hamiltonian approach, through a calculation of the classical Poisson brackets among the Fourier mode components of the string embedding coordinates and a consistent quantization procedure, we show that the spacetime coordinates of the string endpoints in the directions parallel and perpendicular to the D-branes both become noncommutative.


2012 ◽  
Vol 27 (13) ◽  
pp. 1250073 ◽  
Author(s):  
A. SHIRZAD ◽  
A. BAKHSHI ◽  
Y. KOOHSARIAN

We give the details of symplectic quantization for a system containing second class constraints. This method is appropriate for imposing infinite series of constraints due to the boundary conditions. We use this method for massive bosonic strings in a background B-field and find the correct expansions of the fields in terms of the physical modes. We have found a canonical basis for this model.


Author(s):  
John W. Coleman

In the design engineering of high performance electromagnetic lenses, the direct conversion of electron optical design data into drawings for reliable hardware is oftentimes difficult, especially in terms of how to mount parts to each other, how to tolerance dimensions, and how to specify finishes. An answer to this is in the use of magnetostatic analytics, corresponding to boundary conditions for the optical design. With such models, the magnetostatic force on a test pole along the axis may be examined, and in this way one may obtain priority listings for holding dimensions, relieving stresses, etc..The development of magnetostatic models most easily proceeds from the derivation of scalar potentials of separate geometric elements. These potentials can then be conbined at will because of the superposition characteristic of conservative force fields.


1981 ◽  
Vol 64 (11) ◽  
pp. 18-26 ◽  
Author(s):  
Tetsuya Nomura ◽  
Nobuhiro Miki ◽  
Nobuo Nagai

2018 ◽  
Vol 103 (9) ◽  
pp. 1019-1038 ◽  
Author(s):  
Lin Wang ◽  
Bradley P. Owens ◽  
Junchao (Jason) Li ◽  
Lihua Shi

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