3,846 research outputs found
Using LISA-like Gravitational Wave Detectors to Search for Primordial Black Holes
Primordial black hole (PBH), which can be naturally produced in the early
universe, remains a promising dark matter candidate . It can merge with a
supermassive black hole (SMBH) in the center of a galaxy and generate
gravitational wave (GW) signals in the favored frequency region of LISA-like
experiments. In this work, we initiate the study on the event rate calculation
for such extreme mass ratio inspirals (EMRI). Including the sensitivities of
various proposed GW detectors, we find that such experiments offer a novel and
outstanding tool to test the scenario where PBH constitutes (fraction of) dark
matter. The PBH energy density fraction of DM () could
potentially be explored as small as . Further, LISA has
the capability to search for PBH mass upto .
Other proposed GW experiments can probe lower PBH mass regime.Comment: 8 pages, 2 figure
Associated production of a neutral top-Higgs with a heavy-quark pair in the \gamma\gamma collisions at ILC
We have studied the associated production processes of a neutral top-Higgs in
the topcolor assisted technicolor model with a pair of heavy quarks in
\gamma\gamma collisions at the International Linear Collider (ILC). We find
that the cross section for t\bar{t}h_t in \gamma\gamma collisions is at the
level of a few fb with the c.m. energy \sqrt{s}=1000 GeV, which is consistent
with the results of the cross section of t\bar{t}H in the standard model and
the cross section of t\bar{t}h in the minimal supersymmetric standard modeland
the little Higgs models. It should be distinct that hundreds of to thousands of
h_t per year can be produced at the ILC, this process of \gamma\gamma \to
t\bar{t}h_t is really interesting in testing the standard model and searching
the signs of technicolor.Comment: 4 pages, 4 figures, some references are adde
Optimal teleportation via thermal entangled states of a two-qubit Heisenberg Chain
We study the optimal teleportation based on Bell measurements via the thermal
states of a two-qubit Heisenberg XXX chain in the presence of
Dzyaloshinsky-Moriya (DM) anisotropic antisymmetric interaction and obtain the
optimal unitary transformation. The explicit expressions of the output state
and the teleportation fidelity are presented and compared with those of the
standard protocol. It is shown that in this protocol the teleportation fidelity
is always larger and unit fidelity is achieved at zero temperature. The DM
interaction can enhance the teleportation fidelity at finite temperatures, as
opposed to the effect of the interaction in the standard protocol. Cases with
other types of anisotropies are also discussed.Comment: Accepted by EP
Proportional fairness in wireless powered CSMA/CA based IoT networks
This paper considers the deployment of a hybrid wireless data/power access
point in an 802.11-based wireless powered IoT network. The proportionally fair
allocation of throughputs across IoT nodes is considered under the constraints
of energy neutrality and CPU capability for each device. The joint optimization
of wireless powering and data communication resources takes the CSMA/CA random
channel access features, e.g. the backoff procedure, collisions, protocol
overhead into account. Numerical results show that the optimized solution can
effectively balance individual throughput across nodes, and meanwhile
proportionally maximize the overall sum throughput under energy constraints.Comment: Accepted by Globecom 201
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