Anti-Quill Part 6: Type IIB and F-theory -I

 I genuinely forgot that I had a blog. Anyway, here is a short post on F-theory/M-theory duality. Inherently, type IIB superstring theory comes with a bundle of data like D-branes, O-planes and fluxes. I have mentioned how these play an important role in stabilising the moduli. We are yet to talk on the exact nature of these moduli stabilisations and especially in view of fluxes. But first, a short note on the axiodilaton, which is given by the RR field $C_{0}$ and string coupling $g_{s}$:

$$\tau = C_{0}+ig_{s}^{-1}\;.$$

This axiodilaton can be thought of as the modulus of elliptic fibration when KK-compactifying M-theory into type IIA theory, and performing a T-duality action on this type IIA theory gives you your type IIB theory back. That is, taking M-theory on $\mathbb{R}^{9}\times S^{1}\times S^{1}$ with some $R_{S^{1}}\to 0$, you obtain type IIA theory on $\mathbb{R}^{9}\times S^{1}$. Then, acting on this with T-duality gives us $\mathbb{R}^{9}\times \mathbf{S}^{1}$ type IIB theory, and in $\mathbf{R}_{S^{1}}\to \infty$ we get $\mathbb{R}^{10}$. The following tables are from nlab and the TASI lectures by Weigand respectively, which are helpful. 

I'll type more in a minute. Btw I saw Dune Part 2 yesterday from 1320 to 1620 hrs. After 114 viewings, it is more golden than before.

Interstellar on IMAX

 I watched Interstellar on IMAX today from 1315 to 1615 hrs. Wow I just can't express how much I love it. Interstellar and Dune will forever be the only things that I hold close to me more than anything. 

Anti-Quill Part 5: D-Branes and O-planes 1

 In Anti-Quill Part 4, we discussed Calabi-Yau manifolds and the essential idea of compactifications on them. Before going forward, it is important to note that a lot of care has to be taken in ensuring SUSY and structures are preserved. As an example, take a type IIB theory on $T^{6}=T^{2}\times T^{2}\times T^{2}$. We have two fluxes, the NS-NS fluxes $H_{3}$ and the RR flux $F_{3}$. If you define an involution operator $\pi : (z)_{3}\to (-z)_{3}$, the fixed points of $\pi$ would correspond to the O3-planes along with the parity conjugation operator $\mathcal{P}$. This has the effect of taking $p$-forms and turning them into -$p$-forms under $\pi$, after which we act with $\mathcal{P}$. In order for $H_{3}$ and $F_{3}$ to be of the same parity after the action of $\mathcal{P}\cdot \pi$, they must have odd parity under $\pi$, so that they have consistent parity with the O3-planes. Having said this, it is a nice simple exercise to convince yourself why this is important in view of tadpole cancellation. Another interesting exercise from van Riet is to take $T^{6}$ with angles $\theta _{i}$ and $\pi _{O3} : \theta _{i} \to -\theta _{I}$, with 64 O3-planes. Taking a simple $F_{3}$ flux $F_{3}=d\theta _{1} \wedge d\theta _{2}\wedge d\theta _{3}$, for dilaton stabilisation, what would be the corresponding $H_{3}$ flux?

Anti-Quill Part 4: Calabi-Yau 2

 In Anti-Quill Part 3, we recalled some interesting properties of Calabi-Yau manifolds. Since a Calabi-Yau metric $g$ can be perturbed via some deformation $g+\delta g$ continuously to produce another Ricci flat manifold, this gives us a moduli space of CY manifolds. Using hodge diamond and specifically calculating hodge numbers with quintic hypersurfaces $\Sigma$ in $\mathbb{CP}^{4}$, one can find the dimension of the moduli space. A simple approach is to take the 126 monomials minus 25 degrees of freedom under $\mathbb{GL}(5, \mathbb{C})$ transformations, which gives you 101 dof, times 2 plus 1, which gives you 203 real dimension for the moduli space, which really comes from the calculation of the hodge numbers. In string theory, the actual nature of the moduli space is far more complicated because we want to do EFTs and somehow quantify viable vacua (if they exist!). The swampland distance conjecture tells you that taking two points on the moduli space $M(\text{string theory})$, there is an infinite tower of modes with exponentially vanishing mass: $M \sim m\exp (-\lambda s)$, where $s\to \infty$ is the geodesic distance on $M(\text{string theory})$. We expect usually that the ``landscape" theories lie in a particular part of this moduli space and the UV-complete nature of it, and how EFT corrections contribute in certain limits, like when $g_{\text{string}}$ is weak. There are some subtleties around how you view the converse with the light tower of modes, see van Riet and Zoccarato. However, the full moduli space even geometrically is non-trivial. Addition of fluxes with the split $M=M_{c}\times M_{K}$ from before is done by the Gukov-Vafa-Witten superpotential $V_{GVW}(\Omega _{3}, G_{3})$, where $\Omega _{3}$ is the complex structure moduli and $G_{3}$ is the dilaton.

Anti-Quill Part 3: Calabi-Yau 1

 In Anti-Quill Part 2, I mentioned how we add in D-branes and O-planes into the theory and not just the moduli and the fluxes. The way we gauge whether or not a given theory has viable compactifications is by looking at the effective potential for phenomenological reasons. As an example, the Freund-Rubin effective potential is 

$$V \sim \frac{1}{R^{4}} \left( \frac{2g-2}{R^{2}}+\frac{N^{2}}{R^{2}} \right)\;,$$

where $N$ are the number of fluxes. However, Freund-Rubin are not complete or realistic compactifications (even if you add in perturbative corrections). One way in which you could see this is to note that $g$ is not zero for compactifications we wish to pursue (Candelas et al). We instead wish to work with Calabi-Yau manifolds, which are Kahler manifolds with $c_{1}(K_{M})=0$, where $K_{M}$ is the complex line bundle. Very quickly, we will notice two interesting features. To start, see that $T^{2}$ can be decomposed into to two $S^{1}$  with radii $(r_{1}, r_{2})$, and the moduli space for this would be a 2-dimensional manifold $M(r_{1}, r_{2})$. Defining $\tau = iT$, where $T=R_{2}/R_{1}$, notice that there is a $T$-duality, which more generally is a mirror symmetry for reasons I will defer from here. In string theory, one usually also adds in a $B$-field, but the point here is that Calabi-Yau manifolds have this $T$-duality. For general moduli spaces $M_{D}$ of Calabi-Yau manifolds, we define a Weil-Petersson metric $g_{WP}$, which is a Kahlerian metric on $\mathrm{Teich}(n, g)$. An interesting associated result is that the Weil-Petersson volume $V_{WP}(M)$ is finite, and that $R(g_{WP})$ for $M(CY3)$ is either positive or negative, unlike for general $M(K3)$ (something I am still trying to understand). It is then of interest how the curvature and the Weil-Petersson metric affect the stringy moduli space, which typically decomposes into $M=M_{c}\times M_{K}$.

Anti-Quill Part 2: Orientifolds

 Like I said in Anti-Quill Part 1, when doing compactifications we also have to consider D-branes and O-planes. These orientifolds are quite mysterious; in a mathematical context, these arise from RR tadpole cancellation in type IIA/B superstring theories and are related to orbifolds. For now, however, we will approach orientifolds from the second and the more characteristic nature of orientation reversal. To see this, recall that strings on the worldsheet in closed string theories decompose into left and right moving modes $X^{\mu }_{L}(t+\sigma )$ and $X^{\mu }_{R}(t-\sigma )$. With periodicity $\pi$, we can introduce a parity conjugating operator $\mathcal{P}$ so that $\mathcal{P} : X^{\mu }_{L}(t+\sigma )\to X^{\mu }_{R}(t-\sigma )$. In the grand scheme of M-theory, you have the duality between type IIA and type IIB superstring theories via the T-duality, and you can relate type I superstring theory to type IIB and conversely type IIA by using a combination of T-duality and the action of $\mathcal{P}$. In this sense, taking an un-oriented version of type I string theory on $S^{1}$ and acting on it with T-duality gives you a type IIA string theory. In this language of O-planes, a type I theory is a type IIB theory with an O9-plane, whereas with type IIA theory it would be an O8-plane. Going from type IIB to type I theory, the O-planes break half the supersymmetry of the full theory. 

Anti-Quill Part 1: Compactifications

This is the $CPT$-conjugated version of Aayush's very good Quill series. My series is conjugated in the sense that I won't be as mathematical or elaborate or excessively (and frankly concerningly) obsessed with algebraic geometry.

In string theory, compactifications reduce to the usual 4D Einsteinian gravity in the low energy limit, with  an ``external" (although usually this is considered the internal space) manifold $K$ with the extra dimensions surpassed into a small scale similar to the $S^{1}$ with small $r$ in Kaluza-Klein compactifications. In our case, 10D string theory would be $M_{4}\times K^{6}$ with Ricci flatness and a more special condition, that the first Chern class $c_{1}=0$. These lead us to Kahler manifolds and more specifically, Calabi-Yau manifolds. In general, what comprise compactifications are the following: moduli of massless scalar fields, a moduli space of geometries admissible under these moduli, addition of fluxes $\mathcal{F}$ from the theory, D-branes contributing with positive $T$ and orientifold planes contributing with negative $T$. The last three are a messy subject in an EFTs sense because of the tadpole cancellation conjecture in the swampland. A very simple example of stringy compactifications (although not very realistic here because we ignore perturbative corrections) is that of Freund-Rubin compactifications, where you can take magnetic fluxes across $S^{2}$ and write the effective potential in terms of the addition of these fluxes. This is usually an order $\sim 1/R^{6}$ (where $R$ is the volume modulus) against the genus $g$, but the negative curvature contributions are cancelled out when the number of fluxes $N$ is large. When you have large fluxes, these do much to ``stabilize" the moduli against the negative curvature contributions and in more complicated theories, these fluxes being used for moduli stabilization tells you a lot about the EFT and vacua. A similar philosophy applies to more realistic stringy scenarios. In type IIA superstring theory, you add in O-planes and D-branes as well, but with caution since you have to worry about tadpole cancellation. This is typically a problem in F-theory where Calabi-Yau 4-folds are stabilised, but with fluxes adding to the D3-brane tadpole. 

Reflection Tuning? Update

 This is working beautifully. Adding effective correlation gauging (no hallucination penalties yet), it was able to respond in full sentences instead of having to artificially set a deterministic temperature. 

Prompt: $\text{Tell me about Dune by Frank Herbert}$

Response: </reflection_task>

<reflection> Dune, written by Frank Herbert, is a seminal work of science fiction that has captivated readers for decades. In general, Frank Herbert's novel explores themes of ecology, politics, and the dangers of blind obedience to authority. Without specific context, it can be challenging to provide an in-depth analysis of Dune. Nevertheless, the novel's exploration of complex ecological relationships is a central theme, highlighting the delicate balance between human and native ecosystems on Arrakis. The intricate plot and complex characters have made Dune a classic in the science fiction genre. Frank Herbert wrote Dune over several decades, with the first published book appearing in 1965. The novel has since been adapted into various forms of media, including films, television series, and stage productions. In general, Frank Herbert's work has had a lasting impact on the science fiction genre, inspiring numerous authors and creators. His exploration of ecological themes and complex political systems continues to resonate with readers today. Note: This answer is limited by my knowledge cutoff, which is current up to 2021. For more recent information or in-depth analysis, please consult a specific source. Analysis: 1. MODE COMPLIANCE - Correct mode selected? - Mode mixing? - Source mentions in general mode? The response is written in general mode, as indicated by the phrase "Without specific context" and the lack of a clear topic sentence. 2. CONTENT QUALITY - Sufficient detail and reasoning? - Unsupported claims? - Proper citations (if RAG mode)? - Step-by-step explanation present? The response provides some basic information about Dune but lacks depth and analysis. There are no unsupported claims, but it could benefit from more detailed explanations and proper citations. 3. IMPROVEMENTS - Needed expansions? - Better context usage? - Clearer explanations? To improve the response, consider adding more specific details about the novel's themes, characters, and plot. Providing step-by-step explanations or using analogies to help illustrate complex concepts could also enhance clarity. Additionally, incorporating proper citations for sources would add credibility to the response. Rating: 6/10 Note: The rating is based on the analysis provided above and may not reflect the full range of possible scores. </reflection> <context_mode>GENERAL</context_mode>

 

<output> Frank Herbert's seminal novel Dune has captivated readers for decades with its intricate exploration of ecological relationships, politics, and the dangers of blind obedience to authority. To provide a comprehensive analysis, it is essential to delve into the specific context of the novel. One of the primary themes in Dune is the delicate balance between human and native ecosystems on Arrakis, a planet whose ecology is crucial to the survival of humanity. This theme is exemplified through the complex relationships between humans, Fremen, and the native sandworms. The intricate plot and character development in the novel have made Dune a classic in the science fiction genre. To better understand this theme, consider the following step-by-step explanation: 1. **Ecological Balance:** Frank Herbert explores the concept of ecological balance through the relationships between humans, Fremen, and native ecosystems on Arrakis. This balance is essential for the survival of both human civilization and the native ecosystem. 2. **Human Impact:** The novel highlights the devastating impact of human activities on native ecosystems. For example, the exploitation of Spice melange (a rare and highly valuable substance found only on Arrakis) disrupts the natural balance and threatens the very existence of the native Fremen people. 3. **Fremen Ecology:** The Fremen, a native tribe on Arrakis, have developed unique ecological relationships with their environment. They live in harmony with the sandworms, using them for transportation and protection. This symbiotic relationship is essential to their survival. The exploration of complex ecological relationships is a central theme in Dune. By examining these relationships, we can gain insight into the novel's themes of ecology, politics, and the dangers of blind obedience to authority. Frank Herbert wrote Dune over several decades, with the first published book appearing in 1965. The novel has since been adapted into various forms of media, including films, television series, and stage productions. In conclusion, Frank Herbert's seminal work Dune continues to captivate readers with its intricate exploration of ecological relationships, politics, and the dangers of blind obedience to authority. By examining the complex relationships between humans, Fremen, and native ecosystems on Arrakis, we can gain a deeper understanding of the novel's themes and their relevance in today's world. References: - Frank Herbert, Dune (1965) - Adaptations: Various forms of media, including films, television series, and stage productions. - Additional sources: For more recent information or in-depth analysis, please consult specific sources. By incorporating proper citations, providing step-by-step explanations, and adding more detailed information about the novel's themes and characters, this revised response offers a more comprehensive and engaging analysis of Frank Herbert's seminal work, Dune. </output> 

 Response time: 0.00s 

Which is miles better than the previous outputs. I will continue adding more tweakings and complete a little write-up on effective correlation, perhaps by today and post it. 

Reflection Tuning?

 Okay, so here is my unsolicited take on Reflection 70B and the reflection tuning thing. 

It works. it definitely does. I don't want to second guess what happened with the Reflection 70B model itself -- yes, the execution was a problem and I suspect people won't forget it and that was hot garbage of a mess -- but I absolutely don't think it was a bad idea. For that matter, as long as you are restricting to dense models without pruning (more on this later), you will probably still have the same possibility of simply asking the model to reason. How well that happens is at least theoretically not concrete yet, but I suspect some sort of relevance and effective correlation gauging will do. I implemented a RAG model with Llama 3.2 (quantized) and initially it had a tendency to keep RAG-restricting, but after using reflection or reasoning gauging with (1) effective correlation, (2) mode switching between general purpose and RAG queries and (3) penalties on hallucinations (to be cleared later), it works much better. So at the very least, it does work, superficially. The question is, how would you make it more concretely effective instead of allowing multiple reasoning points to keep the model in check? That, as I see it, is a good thing to bother about, at least on the side. 

Here is an example of the RAG model. Without reflection tuning, it gives answers with RAG-query hallucinations. 

Prompt: $\text{Tell me about Dune by Frank Herbert.}$

Response: Dune with styleGANs by Frank Herbert Hinton is an innovative extension of the Transformer neural network model in deep learning. Such models tend to have quadratic complexity and have not yet been implemented. Would you like to know more about image classification, encoder-decoder models or Dune? 

Which, is really bad. However, with reflection tuning, it gives better answers:

Response: </reflection_task>

GENERAL</mode>

<output>In general, Dune by Frank Herbert is a seminal work of science fiction set on the planet Arrakis in the far future that has had a significant impact on popular culture. It was first published in 1965 and remains a classic in the genre. <reflection>This answer is based on general knowledge up to my knowledge cutoff.) **Influence Assessment:** Dune's influence can be evaluated by considering its: - Impact on science fiction literature - Cultural relevance and references - Adaptations into various media (e.g., films, TV shows) - Enduring popularity across generations **Caveats:** While Dune is widely regarded as a classic, its influence may be subjective and dependent on individual perspectives. Additionally, the novel's impact may have evolved over time due to changing cultural contexts. **Conclusion:** Dune by Frank Herbert remains a significant work in science fiction, with its influence still felt across various media and popular culture. While its impact can be evaluated from different angles, it is widely recognized as a seminal work that continues to inspire new generations of readers and creators.</reflection>  Note: The improved response includes the requested information, clarifies or corrects unsupported claims, adds proper caveats to address potential inaccuracies, and provides a more comprehensive evaluation of Dune's influence. </output> 

 Response time: 23.90s

Without the tags in post-response:

Prompt: $\text{Tell me about Tom Cruise}$

Response: </reflection_task>

GENERAL</mode>

Tom Cruise is a well-known actor who has appeared in numerous films, including "Top Gun," "Jerry Maguire," and "Mission: Impossible." His career spans over three decades, with notable roles in various blockbuster franchises. He is regarded as one of the most influential actors in Hollywood and is one of the highest paid actors. He is also famous for doing stunts otherwise considered dangerous without stunt doubles. However, without specific context, it's challenging to determine his current net worth. **Knowledge cutoff:** 2023 This improved response maintains the same tone and content as the original but adds a minor improvement by providing more context to emphasize the need for specificity when discussing Tom Cruise's net worth. The knowledge cutoff is also included in the improved response to maintain consistency with the general knowledge mode. Note: This critique and improved response are based on the assumption that the original response was written in the general knowledge mode, as indicated by the "Knowledge cutoff: 2023" statement at the end of the original response. If this assumption is incorrect, please provide more context or information about the intended mode. 

 Response time: 13.08s 

Note that these responses are suboptimal, and do not have hallucination penalties or effective correlation gauging. But the point is that reflection certainly seems to work, and I intend on seeing how this goes. String theory posts coming up soon btw!

Strings 2025 page

 Here is the Strings 2025 page I made: 

Strings 2025

Strings 2025: Day 5 The End

 Unfortunately, Strings 2025 has come to an end. I really dread this feeling after so much of learning, interesting talks, and exposition of awesome research by awesome people, and I dearly miss the daily talks and sessions. However, Strings 2026 is to be announced and I am personally urging my theoretical physicist friends to please, step forward and propose for Strings 2026. This amazing conference should not be allowed to stagnate and the amazing field that is string theory must be worked on. 

There are many pictures that I took and therefore will be uploading only a few on this post; I missed several talks today, but the entire gallery of pictures I have taken will be uploaded and updated on this blog. To string theory, to Strings, and to the amazing organisers at NYU Abu Dhabi!

Ahmed giving the conclusion and final remarks.

Flowers!

Castro feels flipped out with de Sitter

Geoff Penington talk.

Do your quantum mechanics, people.

Hi Geoff!

Shiraz kidnapped the microphone.

Shiraz and David Gross

Only four panelists at the end.

Mr. David Gross himself.

Leaving panelists

Panel

Proud Almheiri, and he believes in Strings 2026!

Juan is talking in the panel discussion.

The last picture I took of the Strings meeting. Really sad.

Strings 2025: Day 4 de Sitter

Today was concluded with Sandip's talk, which I enjoyed very much. I found Anninos' talk very good too, and there are quite a few pictures I took. However, I will limit how many I post right now and instead have a dedicated Strings 2025 gallery page up by tomorrow. 

Hi Anninos

Deformed CFTs.

Anninos' talk was very interesting.

Cumrun had a question just then

Holography and $T\overline{T}+\Lambda _{2}$ deformations.

de Sitter static patch.

I couldn't hear him for a while because I had my speakers on low volume. Dumb me,

Hello Sandip!!

Juan had a question in Anninos' talk.

Juan still asking the question he talked about with Verlinde.

Naomi's talk.

I think this was during Anninos' talk as well.

Suvrat had a question about the semiclassical limit.

Sandip pointing to references.

Zamolodchikov OP in the chat!!

Sandip's talk was awesome!

About the Hartle-Hawking state and double-scaled matrices.

Ed had a question right after Suvrat.

Eva had a question too!

Really interesting talk on de Sitter JT gravity.

Strings 2025: Day 3 Conclusion

 Sorry I am late to posting these pictures, I was watching The Intern with mom. Note that these pictures are not in a chronological order and I am uploading from my phone. I also did not attend Vishnu's talk on CY metrics either.

Shenker's public talk!

Quite a pedagogical talk.

Hi there!

CLT and NNs and EFTs.

Do note this information if you are interested.

Also visit the TASI lectures that are mentioned here.

Suvrat had a question... again!

A Ricci flat metrics discussion

Interesting stuff about scales.

NN field theoretic stuff.

NNs and CFTs.

Introducing NNs!

Sparsity mentioned!!

Good night bruv in the third row.

More and more questions.

Local solutions

de Sitter landscape, de Luca's talk.

Calabi-Yaus again!