#Pseudo-Holography
Explore tagged Tumblr posts
Video
tumblr
Communication Tool (Video) Produced for Case Study: psHolix (IBO on HYBSE)
News just in: psHolix, holographic display technology, which is considered to be the next breakthrough in the 3D display industry, is now ready to enter the market, and is set to transform our lives. Now, thanks to their pioneering efforts, in the not too distant future, every display on our smartphones, tablets, monitors, TVs and cars, will be spatial. This awesome news is the most exciting transformation in the display world in recent years, and marks the greatest breakthrough for displays and monitors since the advent of HDR.
1 note
·
View note
Link
If only they could both stop thinking about what had happened. Then perhaps it wouldn't need to happen again.
But they can't stop thinking about it, and what it didn't mean, and what it won't mean when they do it again.
In short, Rimmer and Lister continue to take advantage of the benefits of holography, and continue to ignore anything that starts with 'fee-' and ends with '-lings'.
-
Look, I have no self-control. I wrote another fic about Rimmer and Lister having pseudo-sex.
What can you do?
Enjoy!
#red dwarf#rimmer/lister#clipped fics#arnold rimmer#dave lister#and the cat because i love him#also holly appears#this fic marks the largest number of fics I've ever posted for a fandom#so i'm buying a new notebook tonight lads#I mean 3 doesnt seem like a big amount but FINALLY i've focused enough to get three finished
7 notes
·
View notes
Text
Namaskar 🙏 12/28/2Q21 Q9:28 Ante Meridian. Transformational invites an acquiescence for the mind’s acquiescence for the beyond depth of field. does AM and PM Mean? - WorldAtlas
Search domain worldatlas.comhttps://www.worldatlas.com › articles › what-does-am-and-pm-mean.html
The 12-hour system is a unique time principle which divides the twenty-four hours in a day into 2 phases, a.m. and p.m. The a.m. is derived from the Latin term ante-meridiem which refers to "before noon," while p.m. is derived from post meridiem which means "past midday". And inclusive research is in formation as this is being researched on my MacBook… sea’ ya !
Updates:
When is time ? Even what is time ?
Namaskar 🙏 12/28/2Q21 Q9:28 Ante Meridian. Transformational invites an acquiescence for the mind’s acquiescence for the beyond depth of field. does AM and PM Mean? - WorldAtlas
does AM and PM Mean? - WorldAtlas
https://www.worldatlas.com › articles › what-does-am-and-pm-mean.html
The 12-hour system is a unique time principle which divides the twenty-four hours in a day into 2 phases, a.m. and p.m. The a.m. is derived from the Latin term ante-meridiem which refers to "before noon," while p.m. is derived from post meridiem which means "past midday". The science used is pseudo-science. In accurate as matter does not form cells, matter Forms cells. Only shared this clip for the contrivances of better visual placement of the subject matter regarding time and space/space/time.
https://youtu.be/vwObck9twes
by Zeeya Merali
28 August 2013
from Nature Website
Many researchers believe
that physics will not be complete
until it can explain not just the behavior of space and time,
but where these entities come from.
“Imagine waking up one day and realizing that you actually live inside a computer game,” says Mark Van Raamsdonk, describing what sounds like a pitch for a science-fiction film.
But for Mark Van Raamsdonk, a physicist at the University of British Columbia in Vancouver, Canada, this scenario is a way to think about reality.
If it is true, he says,
“everything around us - the whole three-dimensional physical world - is an illusion born from information encoded elsewhere, on a two-dimensional chip”.
That would make our Universe, with its three spatial dimensions, a kind of hologram, projected from a substrate that exists only in lower dimensions.
This 'holographic principle' is strange even by the usual standards of theoretical physics. But Van Raamsdonk is one of a small band of researchers who think that the usual ideas are not yet strange enough.
If nothing else, they say, neither of the two great pillars of modern physics - general relativity, which describes gravity as a curvature of space and time, and quantum mechanics, which governs the atomic realm - gives any account for the existence of space and time. Neither does string theory, which describes elementary threads of energy.
Van Raamsdonk and his colleagues are convinced that physics will not be complete until it can explain how space and time emerge from something more fundamental - a project that will require concepts at least as audacious as holography.
They argue that such a radical reconceptualization of reality is the only way to explain what happens when the infinitely dense 'singularity' at the core of a black hole distorts the fabric of space-time beyond all recognition, or how researchers can unify atomic-level quantum theory and planet-level general relativity - a project that has resisted theorists' efforts for generations.
“All our experiences tell us we shouldn't have two dramatically different conceptions of reality - there must be one huge overarching theory,” says Abhay Ashtekar, a physicist at Pennsylvania State University in University Park.
Finding that one huge theory is a daunting challenge.
Here, Nature explores some promising lines of attack - as well as some of the emerging ideas about how to test these concepts.
Gravity as thermodynamics
One of the most obvious questions to ask is whether this endeavor is a fool's errand. Where is the evidence that there actually is anything more fundamental than space and time?
A provocative hint comes from a series of startling discoveries made in the early 1970s, when it became clear that quantum mechanics and gravity were intimately intertwined with thermodynamics, the science of heat.
In 1974, most famously, Stephen Hawking of the University of Cambridge, UK, showed that quantum effects in the space around a black hole will cause it to spew out radiation as if it was hot.
Other physicists quickly determined that this phenomenon was quite general. Even in completely empty space, they found, an astronaut undergoing acceleration would perceive that he or she was surrounded by a heat bath. The effect would be too small to be perceptible for any acceleration achievable by rockets, but it seemed to be fundamental.
If quantum theory and general relativity are correct - and both have been abundantly corroborated by experiment - then the existence of Hawking radiation seemed inescapable.
A second key discovery was closely related. In standard thermodynamics, an object can radiate heat only by decreasing its entropy, a measure of the number of quantum states inside it.
And so it is with black holes:
even before Hawking's 1974 paper, Jacob Bekenstein, now at the Hebrew University of Jerusalem, had shown that black holes possess entropy.
But there was a difference. In most objects, the entropy is proportional to the number of atoms the object contains, and thus to its volume.
But a black hole's entropy turned out to be proportional to the surface area of its event horizon - the boundary out of which not even light can escape. It was as if that surface somehow encoded information about what was inside, just as a two-dimensional hologram encodes a three-dimensional image.
In 1995, Ted Jacobson, a physicist at the University of Maryland in College Park, combined these two findings, and postulated that every point in space lies on a tiny 'black-hole horizon' that also obeys the entropy-area relationship.
From that, he found, the mathematics yielded Einstein's equations of general relativity - but using only thermodynamic concepts, not the idea of bending space-time.1
“This seemed to say something deep about the origins of gravity,” says Jacobson.
In particular, the laws of thermodynamics are statistical in nature - a macroscopic average over the motions of myriad atoms and molecules - so his result suggested that gravity is also statistical, a macroscopic approximation to the unseen constituents of space and time.
In 2010, this idea was taken a step further by Erik Verlinde, a string theorist at the University of Amsterdam, who showed 2 that the statistical thermodynamics of the space-time constituents - whatever they turned out to be - could automatically generate Newton's law of gravitational attraction.
And in separate work, Thanu Padmanabhan, a cosmologist at the Inter-University Centre for Astronomy and Astrophysics in Pune, India, showed 3 that Einstein's equations can be rewritten in a form that makes them identical to the laws of thermodynamics - as can many alternative theories of gravity.
Padmanabhan is currently extending the thermodynamic approach in an effort to explain the origin and magnitude of dark energy:
a mysterious cosmic force that is accelerating the Universe's expansion.
Testing such ideas empirically will be extremely difficult.
In the same way that water looks perfectly smooth and fluid until it is observed on the scale of its molecules - a fraction of a nanometer - estimates suggest that space-time will look continuous all the way down to the Planck scale: roughly 10-35 meters, or some 20 orders of magnitude smaller than a proton.
But it may not be impossible.
One often-mentioned way to test whether space-time is made of discrete constituents is to look for delays as high-energy photons travel to Earth from distant cosmic events such as supernovae and γ-ray bursts. In effect, the shortest-wavelength photons would sense the discreteness as a subtle bumpiness in the road they had to travel, which would slow them down ever so slightly.
Giovanni Amelino-Camelia, a quantum-gravity researcher at the University of Rome, and his colleagues have found 4 hints of just such delays in the photons from a γ-ray burst recorded in April.
The results are not definitive, says Amelino-Camelia, but the group plans to expand its search to look at the travel times of high-energy neutrinos produced by cosmic events.
He says that if theories cannot be tested,
“then to me, they are not science. They are just religious beliefs, and they hold no interest for me.”
Other physicists are looking at laboratory tests.
In 2012, for example, researchers from the University of Vienna and Imperial College London proposed 5 a tabletop experiment in which a microscopic mirror would be moved around with lasers.
They argued that Planck-scale granularities in space-time would produce detectable changes in the light reflected from the mirror (see Nature, Single photon could detect quantum-scale black holes).
Loop quantum gravity
Even if it is correct, the thermodynamic approach says nothing about what the fundamental constituents of space and time might be.
If space-time is a fabric, so to speak, then what are its threads? One possible answer is quite literal.
The theory of loop quantum gravity, which has been under development since the mid-1980s by Abhay Ashtekar and others, describes the fabric of space-time as an evolving spider's web of strands that carry information about the quantized areas and volumes of the regions they pass through. 6
The individual strands of the web must eventually join their ends to form loops - hence the theory's name - but have nothing to do with the much better-known strings of string theory. The latter move around in space-time, whereas strands actually are space-time: the information they carry defines the shape of the space-time fabric in their vicinity.
Because the loops are quantum objects, however, they also define a minimum unit of area in much the same way that ordinary quantum mechanics defines a minimum ground-state energy for an electron in a hydrogen atom.
This quantum of area is a patch roughly one Planck scale on a side. Try to insert an extra strand that carries less area, and it will simply disconnect from the rest of the web.
It will not be able to link to anything else, and will effectively drop out of space-time.
Loop quantum gravity
This simulation shows how space evolves in loop quantum gravity. The colors of the faces of the tetrahedra indicate how much area exists at that given point, at a particular moment of time.
One welcome consequence of a minimum area is that loop quantum gravity cannot squeeze an infinite amount of curvature onto an infinitesimal point.
This means that it cannot produce the kind of singularities that cause Einstein's equations of general relativity to break down at the instant of the Big Bang and at the centers of black holes.
In 2006, Ashtekar and his colleagues reported 7 a series of simulations that took advantage of that fact, using the loop quantum gravity version of Einstein's equations to run the clock backwards and visualize what happened before the Big Bang. The reversed cosmos contracted towards the Big Bang, as expected.
But as it approached the fundamental size limit dictated by loop quantum gravity, a repulsive force kicked in and kept the singularity open, turning it into a tunnel to a cosmos that preceded our own.
This year, physicists Rodolfo Gambini at the Uruguayan University of the Republic in Montevideo and Jorge Pullin at Louisiana State University in Baton Rouge reported 8 a similar simulation for a black hole.
They found that an observer travelling deep into the heart of a black hole would encounter not a singularity, but a thin space-time tunnel leading to another part of space.
“Getting rid of the singularity problem is a significant achievement,” says Ashtekar,
...who is working with other researchers to identify signatures that would have been left by a bounce, rather than a bang, on the cosmic microwave background - the radiation left over from the Universe's massive expansion in its infant moments.
Loop quantum gravity is not a complete unified theory, because it does not include any other forces. Furthermore, physicists have yet to show how ordinary space-time would emerge from such a web of information.
But Daniele Oriti, a physicist at the Max Planck Institute for Gravitational Physics in Golm, Germany, is hoping to find inspiration in the work of condensed-matter physicists, who have produced exotic phases of matter that undergo transitions described by quantum field theory.
Oriti and his colleagues are searching for formulae to describe how the Universe might similarly change phase, transitioning from a set of discrete loops to a smooth and continuous space-time.
“It is early days and our job is hard because we are fishes swimming in the fluid at the same time as trying to understand it,” says Oriti.
Causal sets
Such frustrations have led some investigators to pursue a minimalist program known as causal set theory.
Pioneered by Rafael Sorkin, a physicist at the Perimeter Institute in Waterloo, Canada, the theory postulates that the building blocks of space-time are simple mathematical points that are connected by links, with each link pointing from past to future. Such a link is a bare-bones representation of causality, meaning that an earlier point can affect a later one, but not vice versa.
The resulting network is like a growing tree that gradually builds up into space-time.
“You can think of space emerging from points in a similar way to temperature emerging from atoms,” says Sorkin. “It doesn't make sense to ask, 'What's the temperature of a single atom?' You need a collection for the concept to have meaning.”
In the late 1980s, Sorkin used this framework to estimate 9 the number of points that the observable Universe should contain, and reasoned that they should give rise to a small intrinsic energy that causes the Universe to accelerate its expansion.
A few years later, the discovery of dark energy confirmed his guess.
“People often think that quantum gravity cannot make testable predictions, but here's a case where it did,” says Joe Henson, a quantum-gravity researcher at Imperial College London.
“If the value of dark energy had been larger, or zero, causal set theory would have been ruled out.”
Causal dynamical triangulations
That hardly constituted proof, however, and causal set theory has offered few other predictions that could be tested.
Some physicists have found it much more fruitful to use computer simulations. The idea, which dates back to the early 1990s, is to approximate the unknown fundamental constituents with tiny chunks of ordinary space-time caught up in a roiling sea of quantum fluctuations, and to follow how these chunks spontaneously glue themselves together into larger structures.
The earliest efforts were disappointing, says Renate Loll, a physicist now at Radboud University in Nijmegen, the Netherlands.
The space-time building blocks were simple hyper-pyramids - four-dimensional counterparts to three-dimensional tetrahedrons - and the simulation's gluing rules allowed them to combine freely.
The result was a series of bizarre 'universes' that had far too many dimensions (or too few), and that folded back on themselves or broke into pieces.
“It was a free-for-all that gave back nothing that resembles what we see around us,” says Loll.
Casual dynamical triangulation
Casual dynamical triangulation uses just two dimensions: one of space and one of time. The video shows two-dimensional universes generated by pieces of space assembling themselves according to quantum rules. Each colour represent a slice through the universe at particular time after the Big Bang, which is depicted as a tiny black ball.
But, like Sorkin, Loll and her colleagues found that adding causality changed everything.
After all, says Loll, the dimension of time is not quite like the three dimensions of space.
“We cannot travel back and forth in time,” she says.
So the team changed its simulations to ensure that effects could not come before their cause - and found that the space-time chunks started consistently assembling themselves into smooth four-dimensional universes with properties similar to our own.10
Intriguingly, the simulations also hint that soon after the Big Bang, the Universe went through an infant phase with only two dimensions - one of space and one of time. This prediction has also been made independently by others attempting to derive equations of quantum gravity, and even some who suggest that the appearance of dark energy is a sign that our Universe is now growing a fourth spatial dimension.
Others have shown that a two-dimensional phase in the early Universe would create patterns similar to those already seen in the cosmic microwave background.
Holography
Meanwhile, Van Raamsdonk has proposed a very different idea about the emergence of space-time, based on the holographic principle.
Inspired by the hologram-like way that black holes store all their entropy at the surface, this principle was first given an explicit mathematical form by Juan Maldacena, a string theorist at the Institute of Advanced Study in Princeton, New Jersey, who published 11 his influential model of a holographic universe in 1998.
In that model, the three-dimensional interior of the universe contains strings and black holes governed only by gravity, whereas its two-dimensional boundary contains elementary particles and fields that obey ordinary quantum laws without gravity.
Hypothetical residents of the three-dimensional space would never see this boundary, because it would be infinitely far away.
But that does not affect the mathematics: anything happening in the three-dimensional universe can be described equally well by equations in the two-dimensional boundary, and vice versa.
In 2010, Van Raamsdonk studied what that means when quantum particles on the boundary are 'entangled' - meaning that measurements made on one inevitably affect the other. 12
He discovered that if every particle entanglement between two separate regions of the boundary is steadily reduced to zero, so that the quantum links between the two disappear, the three-dimensional space responds by gradually dividing itself like a splitting cell, until the last, thin connection between the two halves snaps.
Repeating that process will subdivide the three-dimensional space again and again, while the two-dimensional boundary stays connected.
So, in effect, Van Raamsdonk concluded, the three-dimensional universe is being held together by quantum entanglement on the boundary - which means that in some sense, quantum entanglement and space-time are the same thing.
Or, as Maldacena puts it:
“This suggests that quantum is the most fundamental, and space-time emerges from it.”
References
1 Jacobson, T. Phys. Rev. Lett. 75, 1260–1263 (1995)
2 Verlinde, E. J. High Energy Phys. http://dx.doi.org/10.1007/JHEP04( class="year">2011)029 (2011)
3 Padmanabhan, T. Rep. Prog. Phys. 73, 046901 (2010)
4 Amelino-Camelia, G., Fiore, F., Guetta, D. & Puccetti, S. preprint at http://arxiv.org/abs/1305.2626 (2013).
5 Pikovski, I., Vanner, M. R., Aspelmeyer, M., Kim, M. S. & Brukner, Č. Nature Phys. 8, 393–397 (2012)
6 Ashtekar, A. preprint at http://arxiv.org/abs/1201.4598 (2012)
7 Ashtekar, A., Pawlowski, T. & Singh, P. Phys. Rev. Lett. 96, 141301 (2006)
8 Gambini, R. & Pullin, J. Phys. Rev. Lett. 110, 211301 (2013)
9 Ahmed, M., Dodelson, S., Greene, P. B. & Sorkin, R. Phys. Rev. D 69, 103523 (2004)
10 Ambjørn, J., Jurkiewicz, J. & Loll, R. Phys. Rev. Lett. 93, 131301 (2004)
11 Maldacena, J. M. Adv. Theor. Math. Phys. 2, 231–252 (1998)
12 Raamsdonk, M. V. Gen. Rel. Grav. 42, 2323–2329 (2010)
These thoughts and or the need for relinquishing these readings or realities serve a duopoly/duality of purpose [s]. For his reality [“?”] to be Removed, placing its constructs in view of the reader too. Whoever’s observation also has questioned the science. As by now questioning either is validated or the hidden is recognized as just that. The beautiful truth is that everything else is just a beautiful lie actively created/built/manufactured for the intrinsically amazed frequencies. The Hu-mane-be-ing. Then the consciousness of questioning further asks, inquisitively: what or why is this here (?)
Not anymore altruistically investigating. Evidently misdirection and theft by way of deception becomes more evident. This chessboard/game, subverts energy and within or without the very vibrations of consciousness and interaction of imagination’s creativity, our experience is energetic. Being creatively designed as each of Terra’s children are now cognizant with or of, this powerful Jedi Knight Force of matter magnetics, has the ability of/for/to control the malleability of everything. To include our own DNA 🧬, which coincidentally presented self healing/activation. And the gatekeepers are aware of our Sovereignty and the gifts of berthed rightness’s spiritual handshake with Mother/Father Supreme Source Creator of Magnetic Service. Not the main lead-in at this point.
A minutely observational footnote these events are complicity’s dance partners. Know as bread and circus…
"Bread and circuses" (or bread and games; from Latin: panem et circenses) is a metonymic phrase referring to superficial appeasement. It is attributed to Juvenal, a Roman poet active in the late first and early second century AD and is used commonly in cultural, particularly political, contexts.
In a political context, the phrase means to generate public approval, not by excellence in public service or public policy, but by diversion, distraction or by satisfying the most immediate or base requirements of a populace,[1] by offering a palliative: for example food (bread) or entertainment (circuses).
In a political context, the phrase means to generate public approval, not by excellence in public service or public policy, but by diversion, distraction or by satisfying the most immediate or base requirements of a populace,[1] by offering a palliative: for example food (bread) or entertainment (circuses).
Juvenal, who coined the phrase, used it to decry the "selfishness" of common people and their neglect of wider concerns.[2][3][4] The phrase implies a population's erosion or ignorance of civic duty as a priority.[5]ignorance of civic duty as a priority.
This still in use practice has indelibly being used to this very day. The Construction of the Colosseum began sometime between A.D. 70 and 72 under the emperor Vespasian. known too as The Flavian Amphitheater.
Our timeline being reset has recalibrated the morality of the construct as well.
Keep watching Warrior Angels. Just know that Warriors never sell their swords.
Namaste 🙏.
![Tumblr media](https://64.media.tumblr.com/7c255588296f7ae9fd8aec66aafbaa72/7326786ab2ee6387-b8/s540x810/d23dabea78fe45a04936c751a902d94ccf0975f7.jpg)
![Tumblr media](https://64.media.tumblr.com/5bcd336fcb44735308fa383997525639/7326786ab2ee6387-85/s540x810/d0463cda645ade65d3539e030b4c3e02c5923671.jpg)
0 notes
Text
Sexbot Aesthetics & Design: Crystal Chapter
Dull human charm paled in comparison with the aethereal nymphets of mythology, now assembled out of silicon and dream.
Why? Because we can.
CRYSTALS
THE QUESTION OF TEXTURE
Mammalian sensibilities reject frigid marble embraces, craving instead the mild womb-surrogacy of supple and/or pulsating lukewarm flesh. Mercifully, several technological breakthroughs have made crystalloid concubots viable despite this biological weakness.
Firstly, advancements in material science have pioneered the production of soft pseudo-jewels, moss-textured gem-meats with malleability levels ranging from hard plastic to clay. Heated by internal electronics, these artificial tissues satisfy primate desires without compromising the geological aesthetic.
Secondly, cyborg prosthetics and other enhancements have broadened the spectrum of enticing experiences. Custom nervous systems and specialized mechalimbs are capable of shifting preferences towards the rock-hard coldness and sharp edges of real crystal courtesandroids.
TRANSPARENCY
As holography becomes commonplace, we can expect the fetishization of spectral lovers to burgeon. Gemform lolitrons promise a rewarding synthesis of the ephemeral and the solid, as translucent yet tangible beings; containers of fuckable light.
Transparent bodies which display inner mechanics (pulsing synthetic organs, coils of intestine, hearts programmed to mimic arousal by beating more quickly upon contact with humans—or circuits, batteries, and bundles of cables) are charmingly vulnerable. Pellucid skin suggests the fragility of insect wings or glass, and by revealing viscera initiates a kind of automatic intimacy. Subsequent distortions, insertions, and violations of those insides may be of interest to the user.
COLORS, FLAWS, & LIGHT
One undeniable draw of these tantraumatons is their polychromatism, the vivid colors which elevate them so far above their counterparts, the merely-human sexbots. Jewel-tones and iridescence create attention singularities. Lightplay on glimmering folds of skin is hypnotic, arrests time and space. They have the presence of aliens, nymphs, godlings, and may serve as bizarre glass sculptures when powered-down.
While some prefer the coherence of a single-color, models with components based on different gems are refreshingly bright, like multi-colored plastic toys: puzzles of topaz, emerald, and sapphire, each limb a different hue. Others imitate the entwined growth of natural crystals (red cubes of galkhaite in quartz shale) or its emergence from opaque stone (a dark body of polished granite, one limpid arm extruding in an amethyst burst).
Opacity ranges from glossy onyx to diamond, with middling stages such as opal and flawed quartz: internal chips and bends that catch the light, wisps of eery glitter, frozen bubbles.
Interactive refraction is a charming feature. Cyber-catamites with prismic qualities will warp rainbows as kaleidoscopic intercourse metronomes.
FORM
The polished facets of euhedral fornicomatons grant them the low-poly appeal of digital characters superimposed over reality. Resolutions vary, from humanoid cubist sculptures to impressionist goddesses, each glittering stroke of paint a miniscule triangle. These contrast sharply with models aiming to capture the beauty of disorganised crystal growth; volcanic mounds of jade, folds of pyrite that crack and blister where skin creases.
Shoulders, eyelashes, and hips are frequently decorated with spar, desert roses, or bristling clusters of needle crystals—however, tumescent mineral blossoms need not be limited to those zones, and their popularity is merely pragmatic, a function of minimizing user interaction with pointed obstructions.
Layered seductroids may have ordinary human exteriors, but reveal geological strata as pelts are removed: fossils hidden between skins, slabs of artificial flesh marked by canyon-like striations. Lubricated geode orifices, installed in the skull, the joints, and replacing the usual holes, drastically improve standard sexbots. A girl opens her mouth to reveal a crystal garden, becoming instantly more fetching.
---
u could have read this on patreon, like, a month ago
23 notes
·
View notes
Text
Surface scanning for 3D dose calculation in intraoperative electron radiation therapy
Abstract
Background
Dose calculations in intraoperative electron radiation therapy (IOERT) rely on the conventional assumption of water-equivalent tissues at the applicator end, which defines a flat irradiation surface. However, the shape of the irradiation surface modifies the dose distribution. Our study explores, for the first time, the use of surface scanning methods for three-dimensional dose calculation of IOERT.
Methods
Two different three-dimensional scanning technologies were evaluated in a simulated IOERT scenario: a tracked conoscopic holography sensor (ConoProbe) and a structured-light three-dimensional scanner (Artec). Dose distributions obtained from computed tomography studies of the surgical field (gold standard) were compared with those calculated under the conventional assumption or from pseudo-computed tomography studies based on surfaces.
Results
In the simulated IOERT scenario, the conventional assumption led to an average gamma pass rate of 39.9% for dose values greater than 10% (two configurations, with and without blood in the surgical field). Results improved when considering surfaces in the dose calculation (88.5% for ConoProbe and 92.9% for Artec).
Conclusions
More accurate three-dimensional dose distributions were obtained when considering surfaces in the dose calculation of the simulated surgical field. The structured-light three-dimensional scanner provided the best results in terms of dose distributions. The findings obtained in this specific experimental setup warrant further research on surface scanning in the IOERT context owing to the clinical interest of improving the documentation of the actual IOERT scenario.
https://ift.tt/2BWHOS5
0 notes
Text
Weyl Anomaly induced Fermi Condensation and Holography. (arXiv:2005.12975v1 [hep-th])
Recently it is found that, due to Weyl anomaly, a background scalar field induces a non-trivial Fermi condensation for theories with Yukawa couplings. For simplicity, the paper consider only scalar type Yukawa coupling and, in the BCFT case, only for a specific boundary condition. In these cases, the Weyl anomaly takes on a simple special form. In this paper, we generalize the results to more general situations. First, we obtain general expressions of Weyl anomaly due to a background scalar and pseudo scalar field in general 4d BCFTs. Then, we derive the general form of Fermi condensation from the Weyl anomaly. It is remarkable that, in general, Fermi condensation is non-zero even if there was not a non-vanishing scalar field background. Finally, we verify our results with free BCFT with Yukawa coupling to scalar and pseudo-scalar background potential with general chiral bag boundary condition and with holographic BCFT. In particular, we obtain the shape and curvature dependence of the Fermi condensate from the holographic one point function.
from gr-qc updates on arXiv.org https://ift.tt/3gnkhvM
0 notes
Text
Specific heat of 2D interacting Majorana fermions from holography. (arXiv:1811.02258v1 [cond-mat.str-el])
Majorana fermions is a fascinating medium for discovering new phases of matter. However, the standard analytical tools are very limited in probing the non-perturbative aspects of interacting Majoranas in more than one dimensions. Here, we employ the holographic correspondence to determine the specific heat of a two-dimensional interacting gapless Majorana system. To perform our analysis we first describe the interactions in terms of a pseudo-scalar torsion field. We then allow fluctuations in the background curvature thus identifying our model with a $(2+1)$-dimensional Anti-de Sitter (AdS) geometry with torsion. By employing the AdS/CFT correspondence, we show that the interacting model is dual to a $(1+1)$-dimensional conformal field theory (CFT) with central charge that depends on the interaction coupling. This non-perturbative result enables us to determine the effect interactions have in the specific heat of the system that can be measured in the laboratory with current technology.
from gr-qc updates on arXiv.org https://ift.tt/2SRP0FK
0 notes
Text
Pinning of longitudinal phonons in holographic helical crystals. (arXiv:1708.08306v2 [hep-th] UPDATED)
We study the spontaneous breaking of translational symmetry and identify the associated Goldstone mode -- a longitudinal phonon -- in a holographic model with Bianchi VII helical symmetry. For the first time in holography, we observe the pinning of this mode after introducing a source for explicit breaking compatible with the helical symmetry of our setup. We study the dispersion relation of the resulting pseudo-Goldstone mode, uncovering how its speed and mass gap depend on the amplitude of the source and temperature. In addition, we extract the optical conductivity as a function of frequency, which reveals a metal-insulator transition as a consequence of the pinning.
from gr-qc updates on arXiv.org http://ift.tt/2wEuSi6
0 notes
Text
Pinning of longitudinal phonons in holographic helical crystals. (arXiv:1708.08306v1 [hep-th])
We study the spontaneous breaking of translational symmetry and identify the associated Goldstone mode -- a longitudinal phonon -- in a holographic model with Bianchi VII helical symmetry. For the first time in holography, we observe the pinning of this mode after introducing a source for explicit breaking compatible with the helical symmetry of our setup. We study the dispersion relation of the resulting pseudo-Goldstone mode, uncovering how its speed and mass gap depend on the amplitude of the source and temperature. In addition, we extract the optical conductivity as a function of frequency, which reveals a metal-insulator transition as a consequence of the pinning.
from gr-qc updates on arXiv.org http://ift.tt/2wEuSi6
0 notes