1,880,523 research outputs found
Improved S/N meter
Signal-to-noise ratios /S/N/ meter containing a variable-frequency notch filter measures noise plus interference in the presence of carrier or modulation signals. A noise source and calibration signal source are included in the instrument for calibration purposes
Classical pattern distributions in and
Classical pattern avoidance and occurrence are well studied in the symmetric
group . In this paper, we provide explicit recurrence
relations to the generating functions counting the number of classical pattern
occurrence in the set of 132-avoiding permutations and the set of 123-avoiding
permutations.Comment: 23 pages, 5 fugure
The Florentin Smarandache Function S(n)
A program SMARAND has been designed to generate S(n) up to a preset limit N (N up to 1000000 has been used in some applications)
Bubbling 1/4 BPS solutions in type IIB and supergravity reductions on S^n x S^n
We extend the construction of bubbling 1/2 BPS solutions of Lin, Lunin and
Maldacena (hep-th/0409174) in two directions. First we enquire whether bubbling
1/2 BPS solutions can be constructed in minimal 6d supergravity and second we
construct solutions that are 1/4 BPS in type IIB. We find that the S^1 x S^1
bosonic reduction of (1,0) 6d supergravity to 4d gravity coupled to 2 scalars
and a gauge field is consistent only provided that the gauge field obeys a
constraint (F \wedge F=0). This is to be contrasted to the case of the S^3 x
S^3 bosonic reduction of type IIB supergravity to 4d gravity, 2 scalars and a
gauge field, where consistency is achieved without imposing any such
constraints. Therefore, in the case of (1,0) 6d supergravity we are able to
construct 1/2 BPS solutions, similar to those derived in type IIB, provided
that this additional constraint is satisfied. This ultimately prohibits the
construction of a family of 1/2 BPS solutions corresponding to a bubbling AdS_3
x S^3 geometry. Returning to type IIB solutions, by turning on an axion-dilaton
field we construct a family of bubbling 1/4 BPS solutions. This corresponds to
the inclusion of back-reacted D7 branes to the solutions of Lin, Lunin and
Maldacena.Comment: 30 pages, Latex citations adde
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